adds reset of octree element population statistics
remove non-locking version of nodeWithUUID()
switch to using SharedNodePointer instead of UUID in octree server send thread
Merge pull request #2545 from ZappoMan/bugfixes

Fixes Voxel Server "stop sending" issue
Couple of quick fixes: reset the skeleton joints when space is pressed as a
last resort to fix broken IK, don't render display names at the origin if
we don't have a skeleton model.
Merge pull request #2548 from ey6es/master

Couple of quick fixes: reset the skeleton joints when space is pressed a...
make sure VoxelServer and ParticleServer are in Agent interest list
Adjust the shadow shader to prevent seeing shadows on the opposite sides of
objects.  Closes #2544.
added back use of nodeWithUUID() instead of sharedpointer
Use the "correct" shadow strategy: include only ambient term when in shadow.
Merge pull request #2550 from birarda/master

fix for Agent interest list
Merge pull request #2555 from ZappoMan/backtotrylockanduuid

added back use of nodeWithUUID() instead of sharedpointer
Merge branch 'master' of https://github.com/highfidelity/hifi
Fix for avatar LOD's getting into a degenerate state.  Don't persist the
avatar LOD, since we adjust it more rapidly.
Make sure we process the model root nodes in alphabetic order.
Make sure we reset our LOD adjustments before we switch back from throttling
the renderer.
tweaks to _processLock to reduce time it's locked
Merge pull request #2556 from ey6es/master

Fix for shadows' showing up on the wrong side of objects.
Merge pull request #2557 from ZappoMan/bugfixes

tweaks to _processLock to reduce time it's locked
hack the NodeList to take the socket on which pinged as active socket