SVY-6883 Try using a real NGClient in editor

moved IPersistChangeListener to shared
SVY-6883 Try using a real NGClient in editor

form url should come from the system so that refreshes can be done. Also
it should be lazy, only set the url when the websocket is ready.
SVY-6883 Try using a real NGClient in editor

start the websocket in a special mode (editor) so that the DesignClient
is started (and that one can interact with eclipse throug the
IDesignerSolutionProvider service)