rename _shapes -> _jointShapes

also stubbed Model::createBoundingShape()
Adding bounding capsule shape for Model

Also:
Cleaned up the automatic geometry LOD loading
Removed staticExtents data member from FBXGeometry
Split debug rendering of bounding shapes from joint shapes
Init bounding Extents for more correct shapes
draw head bounding shape first
bounding shape relative to model's root Joint
Resolve body-body collisions with other avatars
merge upstream/master into avatar-interaction
modify avatar thrust during collisions
Only simulate() Avatar Models when necessary

Also: rebuild collision shapes when Model scale changes
Re-add fullUpdate hint to Model::simulate()
merge upstream/master into avatar-interaction

Conflicts:
	interface/interface_en.ts
Merge pull request #2588 from AndrewMeadows/avatar-interaction

Avatar body-body collisions