[MonoDevelop] One-shot dialogs from add-ins

[Casey Marshall]

I'm working on a version control addin for MonoDevelop 2.0 (beta 2),
and would like to have it pop up a simple dialog requesting the user's
password if needed. I'm able to make the dialog appear OK (I'm using
MessageService.GetPassword, but also tried creating a new Gtk.Dialog
myself), but I can't seem to be able to make it a "one shot" window --
only one instance of the window should appear, and if multiple VC
commands need to execute, they should all wait for the same dialog to
return.

Is it possible to do this? I've tried three different approaches, and
none of them have worked.

Thanks.