Use inttypes.h on VC++ 2013 and up
Warnings will spit out on newer compilers due to PRI* being redefined.
Tested with VC++ 2015 and 2017. [Blog post](https://blogs.msdn.microsoft.com/vcblog/2013/07/19/c99-library-support-in-visual-studio-2013/) describing the defines being added in 2013.
diff --git a/src/windows_port.h b/src/windows_port.h
index 554b9c9..61cf5b7 100644
--- a/src/windows_port.h
+++ b/src/windows_port.h
@@ -109,10 +109,14 @@
#define unlink _unlink
#endif
+#if defined(_MSC_VER) && _MSC_VER >= 1800
+#include <inttypes.h>
+#else
#define PRId32 "d"
#define PRIu32 "u"
#define PRId64 "I64d"
#define PRIu64 "I64u"
+#endif
#if !defined(__MINGW32__) && !defined(__MINGW64__)
#define strtoq _strtoi64
