Made overlays thread safe for write operations, which solved a script
crash.
Added some missing locks to make Overlays thread safe for reading as well.
Use local viewer model for specular.
Added a new lock specific to deleting, and improved safety
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
added if to not track ParticleErase packets
removed updatePacketTimestamp()

..from OctreeQueryNode
Working on cascading shadow maps.
Added getJointCombinedRotation to Models
Fix for shadow map rendering.
Added joints position and combined rotation to scripting interface
Added attaching of model to MyAvatar when close enough
added flag,seq,ts to ParticleErase and ModelErase

... this fixes unreasonable flight-time issue
added flag,seq,st to EnvironmentData, untested

removed/commented out debug prints
Progress on selecting cascades.
safe copy of JointState data
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/highfidelity/hifi into click_drag_attach

Conflicts:
	interface/src/renderer/Model.cpp
removed debug info, cleaned code for pull req