Improved Read/Write Locks on the PhysX Scene
Improved Read/Write Locks on the PhysX Scene

Summary:
Improved read/write locking on the PhysX scene, so that conflicts do no
occurr.

Test Plan: Tested with various OAR on Fedora & Ubuntu; Simian & Standalone

Reviewers: martin, szielinski, rlouden, clattin, kboswell

Differential Revision: http://cr.irl.ucf.edu/D412

ucfistirl/physx-wrapper,ucfistirl/physx-wrapper