fixes for MSVC non-standard C library

strcase => _stricmp
strncase => _strnicmp
strdup => _strdup
snprintf => _snprintf

a compliant snprintf() is supposed to be available
in MS Visual Studio 2015 and later

src/fileformats.c

@@ -53,6 +53,12 @@
 
 
 #include <stdlib.h>
+#if defined(_MSC_VER)
+#include <stdio.h>
+#if _MSC_VER < 1900
+#define snprintf _snprintf
+#endif
+#endif
 
 #include "errors.h"
 #include "global.h"