Add the old Bullet 2.x obsolete demos, and CMake buildsystem files, and gradually move them to newer Bullet 3.x structure

Use statically linked freeglut, instead of dynamic glut for the obsolete Bullet 2.x demos
Add the 'reset' method to b3GpuDynamicsWorld, and use it in the BasicGpuDemo (pretty slow in debug mode, use release mode)
Don't crash in btCollisionWorld, if there is no collision dispatcher

Demos3/BasicGpuDemo/b3GpuDynamicsWorld.h

@@ -12,6 +12,7 @@ class btTypedConstraint;
 
 #include "LinearMath/btAlignedObjectArray.h"
 #include "BulletDynamics/Dynamics/btDynamicsWorld.h"
+#include "Bullet3Common/b3Logging.h"
 
 
 class b3GpuDynamicsWorld : public btDynamicsWorld
@@ -30,9 +31,9 @@ class b3GpuDynamicsWorld : public btDynamicsWorld
 	bool	m_cpuGpuSync;
 	float	m_localTime;
 	class btRigidBody*		m_staticBody;//used for picking and Bullet 2.x compatibility. In Bullet 3.x all constraints have explicitly 2 bodies.
-
 	int findOrRegisterCollisionShape(const btCollisionShape* colShape);
-
+	
+	
 	
 public:
 	b3GpuDynamicsWorld(class b3GpuSapBroadphase* bp,class b3GpuNarrowPhase* np, class b3GpuRigidBodyPipeline* rigidBodyPipeline);
@@ -57,7 +58,6 @@ public:
 	virtual void	addConstraint(btTypedConstraint* constraint, bool disableCollisionsBetweenLinkedBodies=false);
 
 	virtual void	removeConstraint(btTypedConstraint* constraint);
-
 	void	rayTest(const btVector3& rayFromWorld, const btVector3& rayToWorld, RayResultCallback& resultCallback) const;
 
 	btAlignedObjectArray<class btCollisionObject*>& getCollisionObjectArray();
@@ -75,8 +75,6 @@ public:
 		addRigidBody(body);
 	}
 
-	
-
 	virtual void	addAction(btActionInterface* action) 
 	{
 		btAssert(0);
@@ -108,6 +106,8 @@ public:
 
 	///this can be useful to synchronize a single rigid body -> graphics object
 	void	synchronizeSingleMotionState(btRigidBody* body);
+
+	void reset();
 };
 
 #endif //B3_GPU_DYNAMICS_WORLD_H