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

ObsoleteDemos/CharacterDemo/DynamicCharacterController.h

@@ -0,0 +1,55 @@
+#ifndef CHARACTER_CONTROLLER_H
+#define CHARACTER_CONTROLLER_H
+
+#include "LinearMath/btVector3.h"
+
+#include "BulletDynamics/Character/btCharacterControllerInterface.h"
+
+class btCollisionShape;
+class btRigidBody;
+class btCollisionWorld;
+
+///DynamicCharacterController is obsolete/unsupported at the moment
+class DynamicCharacterController : public btCharacterControllerInterface
+{
+protected:
+	btScalar m_halfHeight;
+	btCollisionShape* m_shape;
+	btRigidBody* m_rigidBody;
+
+	btVector3 m_raySource[2];
+	btVector3 m_rayTarget[2];
+	btScalar m_rayLambda[2];
+	btVector3 m_rayNormal[2];
+
+	btScalar m_turnAngle;
+
+	btScalar m_maxLinearVelocity;
+	btScalar m_walkVelocity;
+	btScalar m_turnVelocity;
+public:
+	DynamicCharacterController ();
+	~DynamicCharacterController ();
+	void setup (btScalar height = 2.0, btScalar width = 0.25, btScalar stepHeight = 0.25);
+	void destroy ();
+
+	virtual void reset ();
+	virtual void warp (const btVector3& origin);
+	virtual void registerPairCacheAndDispatcher (btOverlappingPairCache* pairCache, btCollisionDispatcher* dispatcher);
+
+	btCollisionObject* getCollisionObject ();
+
+	void preStep (const btCollisionWorld* collisionWorld);
+	void playerStep (const btCollisionWorld* collisionWorld,btScalar dt,
+					 int forward,
+					 int backward,
+					 int left,
+					 int right,
+					 int jump);
+	bool canJump () const;
+	void jump ();
+
+	bool onGround () const;
+};
+
+#endif