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
Merge branch 'master' of https://github.com/worklist/hifi into octree_server_scaling

Conflicts:
	libraries/shared/src/ResourceCache.cpp
Merge pull request #2149 from ZappoMan/octree_server_scaling

Octree server scaling improvements
Merge branch 'master' of https://github.com/highfidelity/hifi