Several changes to sync Bullet trunk with PlayStation 3 spubullet version

Still needs some cross-platform fixes

src/BulletMultiThreaded/SequentialThreadSupport.h

@@ -85,10 +85,10 @@ public:
 	{
 		return 1;
 	}
-	virtual btBarrier*	createBarrier() { return 0;}
-
-	virtual btCriticalSection* createCriticalSection()  { return 0;};
+	virtual btBarrier*	createBarrier();
 
+	virtual btCriticalSection* createCriticalSection();
+	
 
 };