Collision detection glitches

Actor movement collision detection is currently framerate-dependent, which can lead to certain collisions not being detected if the framerate is low, i.e. the player glitching through an object and then being stuck inside.

http://www.bulletphysics.org/mediawiki-1.5.8/index.php/Framerate_Independence

Bullet's stepSimulation() does support running at a fixed 60HZ and performing interpolation for frames in between, but we're not currently using it. Our character controller would need to be ported to Bullet's interface for kinematic objects.

Related to #2737 (closed)

(RM-1587 from redmine: created on 2014-06-28 by Alexander Bessman, , closed on 2016-02-14 by scrawl ., relates #2737 (closed), duplicates #1867 (closed), duplicates #762 (closed), duplicates #2007 (closed), duplicates #2756 (closed), duplicates #2393 (closed), duplicates #2807 (closed), duplicates #2814 (closed))

Attachments: Save_002___Testing_stuck_between_pillars.omwsave phasing.omwsave