Merge pull request #1971 from ey6es/master

Ignore extra "=1"'s that Faceshift appends to FST files, fall back to default head/body on failure to load.
Fix for #1968: head does not roll
Merge branch 'master' of ssh://github.com/highfidelity/hifi into fix-mouselook
Merge pull request #1976 from AndrewMeadows/fix-mouselook

Fix mouselook roll
Switched from loading FBX and FST simultaneously to loading FST first, then
using its filename and texdir properties (as Faceshift does) to locate the
corresponding model.  Also fixed a bug with the fallback models (they were
invisible after second failure).