* gnome/Gnome.metadata: Hide Druid with_window ctor, map About property. add some null_ok from bug #57948.
* gnome/Druid.custom: implement with_window ctor for subclassing, and
a 3 paramatered version for when you dont care about the returned
window. another 3 parametered version for when you have want null
parent, and a 2 parametered version for the null parent and the
discarding of the window (THANKS MIKE!)
* gnome/Makefile.am: add new custom.
svn path=/trunk/gtk-sharp/; revision=26948