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
Update JSConsole colors
Add console to script editor
make scripted assignments passed in DS config static
Merge branch 'master' of https://github.com/highfidelity/hifi