Compiling and Using JSONCPP on Visual Studio10 wit

I have recently compiled the SVN version of JSONCPP using the VS71 makefiles. It worked, but I get a lot of linker errors
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: __int64 __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::sputn(char const *,__int64)" (?sputn@?$basic_streambuf@DU?$char_traits@D@std@@@std@@QAE_JPBD_J@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: void __thiscall std::basic_ostream<char,struct std::char_traits<char> >::_Osfx(void)" (?_Osfx@?$basic_ostream@DU?$char_traits@D@std@@@std@@QAEXXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: class std::basic_ostream<char,struct std::char_traits<char> > * __thiscall std::basic_ios<char,struct std::char_traits<char> >::tie(void)const " (?tie@?$basic_ios@DU?$char_traits@D@std@@@std@@QBEPAV?$basic_ostream@DU?$char_traits@D@std@@@2@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: void __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::_Init(void)" (?_Init@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IAEXXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::basic_streambuf<char,struct std::char_traits<char> >(void)" (??0?$basic_streambuf@DU?$char_traits@D@std@@@std@@IAE@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: __thiscall std::basic_ostream<char,struct std::char_traits<char> >::basic_ostream<char,struct std::char_traits<char> >(class std::basic_streambuf<char,struct std::char_traits<char> > *,bool)" (??0?$basic_ostream@DU?$char_traits@D@std@@@std@@QAE@PAV?$basic_streambuf@DU?$char_traits@D@std@@@1@_N@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: __thiscall std::basic_ios<char,struct std::char_traits<char> >::basic_ios<char,struct std::char_traits<char> >(void)" (??0?$basic_ios@DU?$char_traits@D@std@@@std@@IAE@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: char __thiscall std::basic_ios<char,struct std::char_traits<char> >::fill(void)const " (?fill@?$basic_ios@DU?$char_traits@D@std@@@std@@QBEDXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: char * __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::_Pninc(void)" (?_Pninc@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IAEPADXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: void __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::setp(char *,char *,char *)" (?setp@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IAEXPAD00@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: void __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::setp(char *,char *)" (?setp@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IAEXPAD0@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: void __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::pbump(int)" (?pbump@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IAEXH@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: char * __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::_Gninc(void)" (?_Gninc@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IAEPADXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: char * __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::epptr(void)const " (?epptr@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IBEPADXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: void __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::setg(char *,char *,char *)" (?setg@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IAEXPAD00@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: void __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::gbump(int)" (?gbump@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IAEXH@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: char * __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::egptr(void)const " (?egptr@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IBEPADXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: char * __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::pptr(void)const " (?pptr@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IBEPADXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: char * __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::pbase(void)const " (?pbase@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IBEPADXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: char * __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::gptr(void)const " (?gptr@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IBEPADXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: char * __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::eback(void)const " (?eback@?$basic_streambuf@DU?$char_traits@D@std@@@std@@IBEPADXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: int __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::sputc(char)" (?sputc@?$basic_streambuf@DU?$char_traits@D@std@@@std@@QAEHD@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: class std::basic_ostream<char,struct std::char_traits<char> > & __thiscall std::basic_ostream<char,struct std::char_traits<char> >::flush(void)" (?flush@?$basic_ostream@DU?$char_traits@D@std@@@std@@QAEAAV12@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: class std::basic_ostream<char,struct std::char_traits<char> > & __thiscall std::basic_ostream<char,struct std::char_traits<char> >::operator<<(int)" (??6?$basic_ostream@DU?$char_traits@D@std@@@std@@QAEAAV01@H@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: virtual __thiscall std::basic_ostream<char,struct std::char_traits<char> >::~basic_ostream<char,struct std::char_traits<char> >(void)" (??1?$basic_ostream@DU?$char_traits@D@std@@@std@@UAE@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: class std::basic_streambuf<char,struct std::char_traits<char> > * __thiscall std::basic_ios<char,struct std::char_traits<char> >::rdbuf(void)const " (?rdbuf@?$basic_ios@DU?$char_traits@D@std@@@std@@QBEPAV?$basic_streambuf@DU?$char_traits@D@std@@@2@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: void __thiscall std::basic_ios<char,struct std::char_traits<char> >::setstate(int,bool)" (?setstate@?$basic_ios@DU?$char_traits@D@std@@@std@@QAEXH_N@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: virtual __thiscall std::basic_ios<char,struct std::char_traits<char> >::~basic_ios<char,struct std::char_traits<char> >(void)" (??1?$basic_ios@DU?$char_traits@D@std@@@std@@UAE@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: virtual void __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::imbue(class std::locale const &)" (?imbue@?$basic_streambuf@DU?$char_traits@D@std@@@std@@MAEXABVlocale@2@@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: virtual int __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::sync(void)" (?sync@?$basic_streambuf@DU?$char_traits@D@std@@@std@@MAEHXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: virtual class std::basic_streambuf<char,struct std::char_traits<char> > * __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::setbuf(char *,__int64)" (?setbuf@?$basic_streambuf@DU?$char_traits@D@std@@@std@@MAEPAV12@PAD_J@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: virtual __int64 __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::xsputn(char const *,__int64)" (?xsputn@?$basic_streambuf@DU?$char_traits@D@std@@@std@@MAE_JPBD_J@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: virtual __int64 __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::xsgetn(char *,__int64)" (?xsgetn@?$basic_streambuf@DU?$char_traits@D@std@@@std@@MAE_JPAD_J@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: virtual int __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::uflow(void)" (?uflow@?$basic_streambuf@DU?$char_traits@D@std@@@std@@MAEHXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "protected: virtual __int64 __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::showmanyc(void)" (?showmanyc@?$basic_streambuf@DU?$char_traits@D@std@@@std@@MAE_JXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: virtual void __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::_Unlock(void)" (?_Unlock@?$basic_streambuf@DU?$char_traits@D@std@@@std@@UAEXXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: virtual void __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::_Lock(void)" (?_Lock@?$basic_streambuf@DU?$char_traits@D@std@@@std@@UAEXXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: virtual __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::~basic_streambuf<char,struct std::char_traits<char> >(void)" (??1?$basic_streambuf@DU?$char_traits@D@std@@@std@@UAE@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: __int64 __thiscall std::ios_base::width(__int64)" (?width@ios_base@std@@QAE_J_J@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: __int64 __thiscall std::ios_base::width(void)const " (?width@ios_base@std@@QBE_JXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: int __thiscall std::ios_base::flags(void)const " (?flags@ios_base@std@@QBEHXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: bool __thiscall std::ios_base::good(void)const " (?good@ios_base@std@@QBE_NXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: int __thiscall std::ios_base::rdstate(void)const " (?rdstate@ios_base@std@@QBEHXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: class std::locale::facet * __thiscall std::locale::facet::_Decref(void)" (?_Decref@facet@locale@std@@QAEPAV123@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: void __thiscall std::locale::facet::_Incref(void)" (?_Incref@facet@locale@std@@QAEXXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: __thiscall std::locale::id::operator unsigned int(void)" (??Bid@locale@std@@QAEIXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: void __thiscall std::_Container_base12::_Orphan_all(void)" (?_Orphan_all@_Container_base12@std@@QAEXXZ) already defined in JSONCPP.lib(json_reader.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: __thiscall std::_Container_base12::~_Container_base12(void)" (??1_Container_base12@std@@QAE@XZ) already defined in JSONCPP.lib(json_reader.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: void __thiscall std::_Container_base0::_Orphan_all(void)" (?_Orphan_all@_Container_base0@std@@QAEXXZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: bool __thiscall std::basic_istream<char,struct std::char_traits<char> >::_Ipfx(bool)" (?_Ipfx@?$basic_istream@DU?$char_traits@D@std@@@std@@QAE_N_N@Z) already defined in JSONCPP.lib(json_reader.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: int __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::snextc(void)" (?snextc@?$basic_streambuf@DU?$char_traits@D@std@@@std@@QAEHXZ) already defined in JSONCPP.lib(json_reader.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: int __thiscall std::basic_streambuf<char,struct std::char_traits<char> >::sgetc(void)" (?sgetc@?$basic_streambuf@DU?$char_traits@D@std@@@std@@QAEHXZ) already defined in JSONCPP.lib(json_reader.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: class std::locale __thiscall std::ios_base::getloc(void)const " (?getloc@ios_base@std@@QBE?AVlocale@2@XZ) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: static unsigned int __cdecl std::ctype<char>::_Getcat(class std::locale::facet const * *,class std::locale const *)" (?_Getcat@?$ctype@D@std@@SAIPAPBVfacet@locale@2@PBV42@@Z) already defined in JSONCPP.lib(json_writer.obj)
1>msvcprt.lib(MSVCP100.dll) : error LNK2005: "public: bool __thiscall std::ctype<char>::is(short,char)const " (?is@?$ctype@D@std@@QBE_NFD@Z) already defined in JSONCPP.lib(json_reader.obj)
1>libcpmt.lib(ios.obj) : error LNK2005: "public: static void __cdecl std::ios_base::_Addstd(class std::ios_base *)" (?_Addstd@ios_base@std@@SAXPAV12@@Z) already defined in msvcprt.lib(MSVCP100.dll)
1>libcpmt.lib(ios.obj) : error LNK2005: "private: static void __cdecl std::ios_base::_Ios_base_dtor(class std::ios_base *)" (?_Ios_base_dtor@ios_base@std@@CAXPAV12@@Z) already defined in msvcprt.lib(MSVCP100.dll)
1>libcpmt.lib(locale0.obj) : error LNK2005: "private: static void __cdecl std::locale::facet::_Facet_Register(class std::locale::facet *)" (?_Facet_Register@facet@locale@std@@CAXPAV123@@Z) already defined in msvcprt.lib(locale0_implib.obj)
1>libcpmt.lib(locale0.obj) : error LNK2005: "private: static class std::locale::_Locimp * __cdecl std::locale::_Getgloballocale(void)" (?_Getgloballocale@locale@std@@CAPAV_Locimp@12@XZ) already defined in msvcprt.lib(MSVCP100.dll)
1>libcpmt.lib(locale0.obj) : error LNK2005: "public: static void __cdecl std::_Locinfo::_Locinfo_dtor(class std::_Locinfo *)" (?_Locinfo_dtor@_Locinfo@std@@SAXPAV12@@Z) already defined in msvcprt.lib(MSVCP100.dll)
1>libcpmt.lib(locale0.obj) : error LNK2005: "public: static void __cdecl std::_Locinfo::_Locinfo_ctor(class std::_Locinfo *,char const *)" (?_Locinfo_ctor@_Locinfo@std@@SAXPAV12@PBD@Z) already defined in msvcprt.lib(MSVCP100.dll)
1>libcpmt.lib(locale0.obj) : error LNK2005: "private: static class std::locale::_Locimp * __cdecl std::locale::_Init(void)" (?_Init@locale@std@@CAPAV_Locimp@12@XZ) already defined in msvcprt.lib(MSVCP100.dll)
1>libcpmt.lib(xlock.obj) : error LNK2005: "public: __thiscall std::_Lockit::_Lockit(int)" (??0_Lockit@std@@QAE@H@Z) already defined in msvcprt.lib(MSVCP100.dll)
1>libcpmt.lib(xlock.obj) : error LNK2005: "public: __thiscall std::_Lockit::~_Lockit(void)" (??1_Lockit@std@@QAE@XZ) already defined in msvcprt.lib(MSVCP100.dll)
1>LIBCMT.lib(setlocal.obj) : error LNK2005: __configthreadlocale already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(hooks.obj) : error LNK2005: "void __cdecl terminate(void)" (?terminate@@YAXXZ) already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(invarg.obj) : error LNK2005: __invoke_watson already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(lconv.obj) : error LNK2005: _localeconv already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(typinfo.obj) : error LNK2005: "public: void __thiscall type_info::_type_info_dtor_internal_method(void)" (?_type_info_dtor_internal_method@type_info@@QAEXXZ) already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(typinfo.obj) : error LNK2005: "private: __thiscall type_info::type_info(class type_info const &)" (??0type_info@@AAE@ABV0@@Z) already defined in MSVCRT.lib(ti_inst.obj)
1>LIBCMT.lib(typinfo.obj) : error LNK2005: "private: class type_info & __thiscall type_info::operator=(class type_info const &)" (??4type_info@@AAEAAV0@ABV0@@Z) already defined in MSVCRT.lib(ti_inst.obj)
1>LIBCMT.lib(mlock.obj) : error LNK2005: __unlock already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(mlock.obj) : error LNK2005: __lock already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(winxfltr.obj) : error LNK2005: __XcptFilter already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(crt0dat.obj) : error LNK2005: __initterm_e already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(crt0dat.obj) : error LNK2005: _exit already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(crt0dat.obj) : error LNK2005: __exit already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(crt0dat.obj) : error LNK2005: __cexit already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(crt0dat.obj) : error LNK2005: __amsg_exit already defined in MSVCRT.lib(MSVCR100.dll)
1>LIBCMT.lib(crt0init.obj) : error LNK2005: ___xi_a already defined in MSVCRT.lib(cinitexe.obj)
1>LIBCMT.lib(crt0init.obj) : error LNK2005: ___xi_z already defined in MSVCRT.lib(cinitexe.obj)
1>LIBCMT.lib(crt0init.obj) : error LNK2005: ___xc_a already defined in MSVCRT.lib(cinitexe.obj)
1>LIBCMT.lib(crt0init.obj) : error LNK2005: ___xc_z already defined in MSVCRT.lib(cinitexe.obj)
1>LIBCMT.lib(crt0.obj) : error LNK2005: _mainCRTStartup already defined in MSVCRT.lib(crtexe.obj)
1>LIBCMT.lib(errmode.obj) : error LNK2005: ___set_app_type already defined in MSVCRT.lib(MSVCR100.dll)
1>LINK : warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library
1>LINK : warning LNK4098: defaultlib 'LIBCMT' conflicts with use of other libs; use /NODEFAULTLIB:library
Further, I need to use boost::multi_array with it, but when I#define _ITERATOR_DEBUG_LEVEL 0, it conflicts with JSONCPP's _ITERATOR_DEBUG_LEVEL 2 (need this for boost::multi_array resize to work). How would I fix this?
All of the errors are indicative of wrong C runtime settings with your builds. Make sure that all of your object files, libraries, etc are compiled with the same runtime setting, that is:
Multithreaded (/MT)
Multithreaded DLL (/MD)
Multithreaded Debug (/MTd)
Multithreaded Debug DLL (/MDd)
If this setting isn't the same for all the projects, you've violated the one definition rule (because each C runtime defines things differently) which would result in the behavior you're seeing.
My guess is that the JSONCPP library is being built assuming the static version of the standard library (/MT), while your code is using the Visual Studio default, which is the dynamically linked version (/MD).
You can change this setting from within Visual Studio by selecting the project properties for your project, going to C/C++ -> Code Generation, and changing the Runtime dropdown box.