Fix for shadows in close-up inset mirror.
FEATURE: Allows detecting simulated cursors in JS, this allows JS-developers to track all cursors separately. By using the deviceID. (deviceID 0 = default mouse-cursor , 1500 and 1501 hydra cursors)
Merge branch 'master' of https://github.com/worklist/hifi
removed unused variable
AbstractControllerScriptingInterface matches ControllerScriptingInterface
Merge pull request #3200 from thoys/feature-multiple-JS-cursors

Feature multiple js cursors
Merge pull request #3199 from ey6es/master

Fix for shadows in close-up inset mirror.
Merge pull request #3205 from birarda/select-library

lowercase the SIXENSE_ROOT_DIR
only override root dir for interface externals if they don't exist
more standardization for external library searches
cleanup HifiLibrarySearchHints cmake macro