Commented on the TODOs, which are helpful in the Tasks tab of Eclipse.
Enhanced XServer to accept InputStream/OutputStream instead of Socket.

Because of this update, PipedInputStream/PipedOutputStream can be used
like a socket.
Changed to show a stack trace before toast.

Showing toast can fail for lack of a looper. If it failed, I did not
know why the service crashed. So a stack trace must be shown at first.
Changed ScreenView not to be a child class of View.

Now X server can be in a service. Users must give width/height of the
view.
Updated the jars to the lastest versions.
Enhanced the service to start X server.