Initial reverb implementation

Conflicts:
	interface/CMakeLists.txt
	interface/src/Audio.cpp
	interface/src/Audio.h
	libraries/script-engine/src/ScriptEngine.cpp
Merge branch 'master' of https://github.com/highfidelity/hifi into reverb
remove deprecated _engine member from ScriptEngine
Fix cmake
Update entitySelectionTools to use camera position/orientation instead of avatar
Fix right/left stretch entity tool
Fix entity tools focus not always using latest entity position
removed old processReceivedAudio method
Merge branch 'master' of https://github.com/highfidelity/hifi into reverb

Conflicts:
	interface/CMakeLists.txt
Added reverb settings to DS settings
Adding the Batch class to GPU
Adding the Batch class to GPU and fixing the compilation issues
grab reverb settings on mixer side
Merge branch 'master' of https://github.com/highfidelity/hifi into reverb
Merge branch 'master' of https://github.com/highfidelity/hifi into reverb
Merge branch 'master' of git://github.com/highfidelity/hifi into entity-tools-new
Merge branch 'master' of https://github.com/highfidelity/hifi into reverb
Merge branch 'master' of https://github.com/highfidelity/hifi into reverb
startign to record all the gl commands in the Batch
Allows Windows users to put SDL2 folder in %HIFI_LIB_DIR% folder (see BUILD.md for info about %HIFI_LIB_DIR% environment variable)