libragephoto: introduce C library port

CMakeLists.txt: fixes for MSVC and C library support
RagePhoto: non C++11 support
RagePhotoC: clarify C instance support in comment
RagePhotoTypedefs: add typedefs for C library

src/RagePhoto.cpp

@@ -970,7 +970,11 @@ bool RagePhoto::saveFile(const std::string &filename, uint32_t photoFormat)
             m_data->error = Error::Uninitialised; // 0
             return false;
         }
+#if (RAGEPHOTO_CXX_STD >= 11) && (__cplusplus >= 201103L)
         ofs << sdata;
+#else
+        ofs.write(sdata.data(), sdata.size());
+#endif
         ok = ofs.good();
         ofs.close();
         return ok;