- add example 3rd-party.js to interact with BBB through JS api

bigbluebutton-client/resources/prod/BigBlueButton.html

bigbluebutton-client/resources/prod/bbb-wrapper.html

bigbluebutton-client/resources/prod/lib/3rd-party.js

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

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

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

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