Do the actual reading of the reply on the worker thread.  Otherwise, when we
read from the cache, we're reading synchronously from a file.  Closes #2171.
Merge branch 'master' of https://github.com/highfidelity/hifi
Render the billboard if we don't have both models.  Closes #2178.
Merge branch 'master' of https://github.com/highfidelity/hifi
Tie the avatar LOD distance multiplier to the LOD parameter calculated for
voxels.
Merge pull request #2179 from ey6es/master

Better frame rates on loading by reading cached data from disk in worker thread, render billboards if we haven't loaded the models yet, use voxel LOD parameter to control avatar LODs, too.