Reinitialize ProjectAccessScreen editors when switching modes

Latest SVN tip of GWT improved the way editors are reused inside
of UiBinder panels. Editors are no longer recreated when setting
the same object into the Driver:

  http://code.google.com/p/google-web-toolkit/issues/detail?id=7038

Work around this by clearing the editors with an empty project
access model object before reloading them with the real model that
is now editable.

Change-Id: Icef5601be9910e920773757beeab8a727e67b881
1 file changed