Added btStackAlloc to Bullet (right now only used by btGjkEpa)
removed default constructors of btCollisionWorld/btDiscreteDynamicsWorld, to reduce link-time dependencies
CompoundShapes are tricky to manage with respect to persistent contact points and swapped order of btCollisionObjects,
During dispatch, finding an algorith etc. order can be swapped.
fixed several other issues, related to SimpleBroadphase (removing a proxy was not working)
Fixed memoryleak in btOptimizedBvh (delete []m_contiguousNodes;)
Changed DemoApplication::localCreateRigidBody, so it adds the rigidbody to the btDynamicsWorld.
Added check for duplicate objects in world when adding.
Added assert to prevent setLinearVelocity on static rigidbodies
Added btCollisionFilterGroups to btBroadphaseProxy
removed duplicate 'btBroadphaseProxy* m_broadphaseProxy;' in btRigidBody
removed two cached optimizations, type in btTransform and cached inverse transform (todo: test performance impact)
committed fixes that make the code adhere to 'who creates it, also destroys it'
* Unused variables.
* Missing newlines at ends of #included files.
* signed int loop variables where the termination condition is an unsigned 'get number of' function.
* 'NULL' used inappropriately for an integer or character constant (NULL is a pointer)
* abstract base classes with no virtual destructor.
* Floating point constants used to initialise integer variables.
Moved optional code to Extras: AlgebraicCCD,EPA,quickstep
Moved SimpleBroadphase data to OverlappingPairCache, and derive both SimpleBroadphase and AxisSweep3 from OverlappingPairCache.
Added ParallelPhysicsEnvironment (prepair more parallel mainloop)
Upgraded hardcoded limit from 1024/8192 to 32766/65535 (max objects / max overlapping pairs)
