move OpenCL initialization for the unit tests in a shared header file, and support some basic command-line arguments

--cl_device=1 --cl_platform=1 --allow_opencl_cpu
add chaindemo, test for mass ratios
restore sleeping/activation mode in featherstone demo
Use _VARIADIC_MAX=10 to avoid Google Test issues with Visual Studio 2012, thanks to Mobeen for the report
Enable verbose printf for unit tests

Demos3/bullet2/ChainDemo/ChainDemo.h

@@ -0,0 +1,31 @@
+#ifndef CHAIN_DEMO_H
+#define CHAIN_DEMO_H
+
+#include "LinearMath/btVector3.h"
+#include "../BasicDemo/Bullet2RigidBodyDemo.h"
+
+
+
+class ChainDemo : public Bullet2RigidBodyDemo
+{
+
+public:
+
+	static BulletDemoInterface* MyCreateFunc(SimpleOpenGL3App* app)
+	{
+		return new ChainDemo(app);
+	}
+
+	ChainDemo(SimpleOpenGL3App* app);
+	virtual ~ChainDemo();
+	
+	void	createGround(int cubeShapeId);
+
+	virtual void	initPhysics();
+	virtual void	exitPhysics();
+	virtual void	renderScene();
+	virtual void	stepSimulation(float dt);
+};
+
+
+#endif //CHAIN_DEMO_H