Bullet 2.15 released, restoring some functionality

[Erwin Coumans]

Updated Bullet 2.15

The recent refactoring removed some functionality, and this released puts some of it back:

* btMotionState (see src/LinearMath)
* large cleanup passing btCollisionObject instead of btBroadphaseProxy
* internal btCollisionDispatcher changes related to btCompoundShape broken during refactoring
much more, just check it out.

older updates/refactoring:
Update Bullet 2.12:
* Fixed leak in btOptimizeBVH
* Cleanup of btRigidBody construction
* added getW() in btQuaternion
* assert when setLinearVelocity is called on btRigidBody
* renamed projectfile library from collada-dom to colladadom

Update Bullet 2.11:
* more demos have been converted to use btDynamicsWorld
* more consistent memory strategy (who creates things needs to delete them)
* removed Extras/PhysicsInterface folder

Complete refactoring of Bullet, and addition of GPU physics demo.
Information about migrating from Bullet 1.x to Bullet 2.x:
http://www.continuousphysics.com/mediaw ... Bullet_2.x

Download sources:
http://www.continuousphysics.com/mediaw ... e=Download
Precompiled win32 Bullet Cylinder stacking & GPU physics demo available:
http://www.continuousphysics.com/ftp/pu ... -win32.zip
Updated Doxygen documentation and Bullet 2.1 User Manual pdf

Thanks Steve Baker for the refactoring help and GPU physics demo!
Please use this Bullet forum if there are any issues