- removed warnings in GLUI, thanks Jorrit Tyberghein for the patch!

- removed memory leaks from BasicDemo and Bullet library (other demos needs to be cleaned up!)
- added memory leak debugging functionality in btAlignedAlloc.h: #define BT_DEBUG_MEMORY_ALLOCATIONS

src/LinearMath/btStackAlloc.h

@@ -50,7 +50,7 @@ public:
 
 		if(usedsize==0)
 		{
-			if(!ischild)		
+			if(!ischild && data)		
 				btAlignedFree(data);
 
 			data				=	0;