Allow unaligned load/store in QVM interpreter/x86 compiler

constructions like (dataMask & ~3) was used to protect against out-of-bound load/store when address is 4-byte closer to dataMask
 but at the same time it effectively cut low address bits for ALL load/store operations which is totally wrong in terms of conformance to ALLOWED (i.e. generated by q3lcc from C sources) low-level operations like packed binary data parsing

code/qcommon/vm_local.h

@@ -170,6 +170,7 @@ struct vm_s {
 
 	byte		*dataBase;
 	int			dataMask;
+	int			dataAlloc;			// actually allocated
 
 	int			stackBottom;		// if programStack < stackBottom, error