New collision flag for persistant collisions.
New collision flag for persistant collisions.

Summary: Will continually makes call to contact report callback while a collision pair is in contact.

Test Plan: Compiles and successfully runs.

Reviewers: clattin, szielinski, ssirigam, martin, kboswell

Reviewed By: clattin, szielinski, ssirigam, martin, kboswell

Differential Revision: http://cr.irl.ucf.edu/D364

ucfistirl/physx-wrapper,ucfistirl/physx-wrapper