- fix problem where JS API isn't called when user becomes viewer

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

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

.../src/org/bigbluebutton/main/model/users/UsersSOService.as

...rg/bigbluebutton/modules/layout/managers/LayoutManager.as

...rg/bigbluebutton/modules/layout/model/LayoutDefinition.as

...igbluebutton/modules/present/business/PresentSOService.as

.../bigbluebutton/modules/present/managers/PresentManager.as

...luebutton/modules/videoconf/maps/VideoEventMapDelegate.as