Merge pull request #2767 from ey6es/master

Allow uploading FBXs without FSTs; a dialog pops up on upload to allow customizing the various properties, with presets for Mixamo/Autodesk avatar generators.  Also enforces texture limits and adds joint indices.
Avatar makes eye contact with the person nearest to gaze direction
merge conflict fix
Correction to actually pick closest
debugging model editing
Merge pull request #2768 from PhilipRosedale/master

Avatar makes eye contact with the person nearest to gaze direction
removed debugging
removed debugging
removed debugging
removed debugging
added sample
Merge pull request #2770 from ZappoMan/modelserver

Fix a couple bugs in Models