X11OpenGLWindow: create stencil buffer for shadows in OpenGL2 mode (OpenGL3 uses shadow maps)

Add 'createCollisionObjectGraphicsObject' API for CommonPhysicsSetup
Add 'pthread' dependency as workaround for NVIDIA graphics driver issue
(see //See https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-319/+bug/1248642
)

Demos/SerializeDemo/SerializeSetup.h

@@ -7,8 +7,9 @@ class SerializeSetup : public CommonRigidBodySetup
 public:
     SerializeSetup();
     virtual ~SerializeSetup();
-    
+
 	virtual void initPhysics(GraphicsPhysicsBridge& gfxBridge);
+	virtual void stepSimulation(float deltaTime);
 };
 
 #endif //SERIALIZE_SETUP_H