- add js api to query if user is publishing cam or not

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

...utton-client/src/org/bigbluebutton/core/EventConstants.as

bigbluebutton-client/src/org/bigbluebutton/core/UsersUtil.as

...g/bigbluebutton/core/events/IsUserPublishingCamRequest.as

...-client/src/org/bigbluebutton/core/vo/CameraSettingsVO.as

...nt/src/org/bigbluebutton/main/api/ExternalApiCallbacks.as

...client/src/org/bigbluebutton/main/api/ExternalApiCalls.as

.../org/bigbluebutton/main/api/maps/ExternalApiEventMap.mxml

...ient/src/org/bigbluebutton/main/model/users/Conference.as