to get ready for...
Start creation of BulletAPITemplate. This defines the abstract interface
functions. Following commits will move over to the new interface.
This will enable switching between the managed and unmanaged version of
Bullet.
debugging.
Linkset bugs fixed where accounting of children would get lost.
Moved scene based vehicle tracking logic from prim to the scene.
Added GetCollisionFlags2 method to BulletSimAPI.
Updated DLLs and SOs.
6dof constraint but eventually others will be exposed so future
features can use all the Bullet capabilities.
Force children to generate a position update when unlinked.
