Make ModelBuilder window a dockable window.

Idea created by 1_MarcBate on Sep 4, 2010

    The ModelBuilder window should be a dockable window so users can better manage their windows if they have multiple models open.  It would also map it easier to see your map while your model is running.  Users can even undock the window so they are floating as they appear now, and probably should be the default if users hadn't previously docked the window somewhere.