some hacking on server performance
Merge branch 'master' of https://github.com/worklist/hifi into octree_server_scaling

Conflicts:
	assignment-client/src/octree/OctreeServer.cpp
	assignment-client/src/octree/OctreeServer.h
fixed some warnings
handle some shutdown cases and reduce time of locking in octree server
When we send data to the avatar mixer, send the tweaked head rotation.  Closes
Merge branch 'master' of https://github.com/worklist/hifi into octree_server_scaling

Conflicts:
	libraries/shared/src/ResourceCache.cpp
Merge branch 'master' of https://github.com/highfidelity/hifi
Merge pull request #2149 from ZappoMan/octree_server_scaling

Octree server scaling improvements
Merge branch 'master' of https://github.com/highfidelity/hifi
Merge pull request #2152 from PhilipRosedale/master

Correct billboards on bots, audio doesn't double play, 50 voice clips!
Merge branch 'master' of https://github.com/highfidelity/hifi
Merge pull request #2151 from ey6es/master

Fix for head rotation tweaking.
cleanup names and fix some warnings
fix warning
Merge pull request #2154 from ZappoMan/warningsfix

fix warning
Merge branch 'master' of https://github.com/worklist/hifi into SvoViewer
fixed more warnings
one more attempt to get this to work
fix warning
Merge pull request #2156 from ZappoMan/warningsfix

fix warning