Fix chat shortcut
Merge pull request #3500 from Atlante45/fix_chat_shortcut

Fix chat shortcut
Fix default eye model calculation to be reliable
Merge pull request #3501 from ey6es/metavoxels

Use the rather elaborate technique described in the Rice papers to find the minimizing point for each cell.
Merge pull request #3502 from ctrlaltdavid/20055

Make default eye model calculation be reliable
Don't bother using a callback to render the eye vectors; just rely on the
post-lighting call to Avatar::render, like everything else.  This should fix
the crash that Philip was seeing (presumably due to avatars' being deleted
during the draw process).
Merge pull request #3504 from ey6es/master

Don't bother using a callback to render the eye vectors; just rely on th...
Use Jacobi eigenvalue algorithm to get eigenvalues/eigenvectors.