Add the option for the btSimulationIslandManager to avoid splitting islands (for constraint solving)

Move the convertContact inside constraint solver to its own method

Demos/BasicDemo/BasicDemo.h

@@ -57,6 +57,8 @@ class BasicDemo : public DemoApplication
 	virtual void clientMoveAndDisplay();
 
 	virtual void displayCallback();
+
+	virtual void keyboardCallback(unsigned char key, int x, int y);
 	
 	static DemoApplication* Create()
 	{