added partial VFS support - enough to read static data from any source

ExternalLibs/ttvfs/VFSInternal.h

@@ -0,0 +1,43 @@
+// VFSInternal.h - misc things that are not required to be visible outside of the library.
+// For conditions of distribution and use, see copyright notice in VFS.h
+
+// !! this file is supposed to be included ONLY from VFS*.cpp files.
+
+#ifndef VFS_INTERNAL_H
+#define VFS_INTERNAL_H
+
+// checks to enforcecorrect including
+#ifdef TTVFS_VFS_H
+#error Oops, TTVFS_VFS_H is defined, someone messed up and included VFS.h wrongly.
+#endif
+
+#include "VFSDefines.h"
+
+#if _MSC_VER
+#   define _CRT_SECURE_NO_WARNINGS
+#   define _CRT_SECURE_NO_DEPRECATE
+#   pragma warning(disable: 4355) // 'this' : used in base member initializer list
+#endif
+
+// this is for POSIX - define before including any stdio headers
+#ifdef VFS_LARGEFILE_SUPPORT
+#    ifndef _MSC_VER
+#        define _FILE_OFFSET_BITS 64
+#    endif
+#endif
+
+
+#include <cstdlib>
+#include <cstdio>
+#include <cstring>
+#include <string>
+
+// this is for MSVC - re-define functions
+#ifdef VFS_LARGEFILE_SUPPORT
+#    ifdef _MSC_VER
+#        define fseek _fseeki64
+#        define ftell _ftelli64
+#    endif
+#endif
+
+#endif