message: Fix MSVC build.
diff: #include <sparsepp/spp_memory.h>
  #endif
  -//#define _STRINGIFY(x) #x
  -//#define ENSURE_STRING_MACRO_ARGUMENT(x) _STRINGIFY(x)
  +// DEFAULT_RESOURCE_DIRECTORY is passed with quotes for non-MSVC compilers, ie,
  +// foo vs "foo".
  +#if defined(_MSC_VER )
  +#define _STRINGIFY(x) #x
  +#define ENSURE_STRING_MACRO_ARGUMENT(x) _STRINGIFY(x)
  +#else
  #define ENSURE_STRING_MACRO_ARGUMENT(x) x
  +#endif
  // See http://stackoverflow.com/a/217605
  void TrimStart(std::string& s) {
  