WinRT: fixed bug whereby SDL would override an app's default orientation

WinRT apps can set a default, preferred orientation via a .appxmanifest file.
SDL was overriding this on app startup, and making the app use all possible
orientations (landscape and portrait).

Thanks to Eric Wing for the heads up on this!

visualtest/include/SDL_visualtest_mischelper.h

@@ -0,0 +1,26 @@
+/**
+ * \file mischelper.c 
+ *
+ * Header with miscellaneous helper functions.
+ */
+
+#ifndef _SDL_visualtest_mischelper_h
+#define _SDL_visualtest_mischelper_h
+
+/* Set up for C function definitions, even when using C++ */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Stores a 32 digit hexadecimal string representing the MD5 hash of the
+ * string \c str in \c hash.
+ */
+void SDLVisualTest_HashString(char* str, char hash[33]);
+
+/* Ends C function definitions when using C++ */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SDL_visualtest_mischelper_h */