mono/xwt — pull request #23 by carlosalberto (2012-02-29 13:50:14+00:00)
Title: [WpfBackend] Correctly arrange the controls in a box backend.

Use a custom Panel instead of Canvas, so have full control
on the positions of the controls (and no side effect). Also,
override ArrangeOverride to refresh the controls, as *required*
by WPF.