Rewrote services to use new message system

-No more shared objects! Now, just message senders and message receivers.
-Slight changes to the model.
-Some classes that were no longer necessary were removed (new info comes in with JSON strings)

-TO DO: Lock settings need to be done properly (had to "fake" some of them on the connect call for the BigBlueButtonConnection.baseConnection.netConnection.connect(...) call :P )
Instead of having the return of addPresentation as void you could have it return a reference to the newly created Presentation object. You then wouldn't have to make the subsequent call to getPresentation.