Add Racket script that lets us stop the server.
Only gimp-dbus needs to update if the tile-stream library changes.
Cleanup of tile stream.c
Fixed bug: The image did not update correctly if we did not completely
  iterage the image.
Whoops.  Forgot tile-stream.h.  Added size parameter to update.
experiments/tile-streams.rkt now uses all of the methods.
Also prints some messages.
Finish implementing tile-stream methods.