Fixes #23: The gui updates of the Cellboard were not done within the AWTEventDispatch thread. You have to use SwingUtilities.invokeLater or inovokeAndWait

Also removed a sleep of 400ms!!! before painting the cells!! now it should show up faster
Probably this is the case for all AsTeRICS GUI widgets??

..> repaints could still be improved, then flickering could be eliminated as well.
Merge branch 'master' of https://github.com/asterics/AsTeRICS