MahApps/MahApps.Metro — pull request #1049 by punker76 (2014-02-19 15:41:56+00:00)
Title: another minor flyout improvements

- set visibility for flyouts to hidden by default should improve
performance and a little bug if a flyout has left position (it's a
short time visible if the main window has animation from right to left)
- we don't need this anymore, because we use ActualWidth and
ActualHeight of the root