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'
Add support to load script engines not based on a file
Add console to menu
Add custom evaluation of commands in ScriptEngine
Add JSConsole
Merge branch 'master' of git://github.com/highfidelity/hifi into 19648

Conflicts:
	interface/src/Application.cpp
	interface/src/Application.h
Add console.ui interface file
Update showConsole -> toggleConsole and change shortcut
Update JSConsole to QWidget
Update console style
Update console style
Added OverlayRenderer class and moved displayOverlay from Application to
OverlayRenderer.
Merge branch 'master' of https://github.com/highfidelity/hifi
Update JSConsole colors
Add console to script editor