Thorough(!) remodeling of the arch/ directory and the contents therein; fixed link-time warnings on GCC and should make things a lot easier to manage. A pile of other random things too, mostly cleanups and getting things to work with the remodeled arch/ directory.

stepmania/src/arch/MemoryCard/MemoryCardDriverThreaded_Windows.h

@@ -20,6 +20,11 @@ private:
 	DWORD m_dwLastLogicalDrives;
 };
 
+#ifdef ARCH_MEMORY_CARD_DRIVER
+#error "More than one MemoryCardDriver included!"
+#endif
+#define ARCH_MEMORY_CARD_DRIVER MemoryCardDriverThreaded_Windows
+
 #endif
 
 /*