adding new icons

removing white background from the presentation icon

removing white background from hdpi presentation icon
add userChangeHandler to SwapCameraMediator
Add userChangeHandler to SwapCameraMediator
Merge branch 'fix-swapcamerabtn' of https://github.com/SenecaCDOT-BigBlueButton/bbb-air-client into fix-swapcamerabtn

Conflicts:
	src/org/bigbluebutton/view/ui/SwapCameraMediator.as