Merge pull request #3295 from capilkey/cc-message-check

bigbluebutton-client/locale/en_US/bbbResources.properties

...bigbluebutton/modules/caption/services/MessageReceiver.as

...c/org/bigbluebutton/modules/caption/views/OptionsTab.mxml

...nt/src/org/bigbluebutton/modules/caption/views/TextTab.as

...c/org/bigbluebutton/modules/chat/views/AddChatTabBox.mxml

...nt/src/org/bigbluebutton/modules/chat/views/ChatView.mxml