Merge pull request #4063 from perroned/webrtc-utils

bigbluebutton-client/resources/prod/lib/verto_extension.js

...bigbluebutton/modules/phone/managers/WebRTCCallManager.as

...g/bigbluebutton/modules/phone/models/WebRTCAudioStatus.as

...utton/modules/screenshare/events/DeskshareToolbarEvent.as

...button/modules/screenshare/managers/ScreenshareManager.as

...on/modules/screenshare/managers/WebRTCDeskshareManager.as

...ebutton/modules/screenshare/maps/ScreenshareEventMap.mxml

...ton/modules/screenshare/maps/WebRTCDeskshareEventMap.mxml

...g/bigbluebutton/modules/screenshare/utils/BrowserCheck.as

...ton/modules/screenshare/utils/WebRTCScreenshareUtility.as