Fix Windows build

src/cguittfont/irrUString.h

@@ -41,7 +41,13 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#ifdef _WIN32
+#define __BYTE_ORDER 0
+#define __LITTLE_ENDIAN 0
+#define __BIG_ENDIAN 1
+#else
 #include <endian.h>
+#endif
 
 #ifdef USTRING_CPP0X
 #	include <utility>