don't show Glow
handle WindowStyle == WindowStyle.None

- no title bar
- no window commands
- no min, max, close
- resize is allowed
introduce UseNoneWindowStyle

because the BorderlessWindowBehavior set the WindowStyle to None !!!
minor documentation
HandleMaximize fix
fix of HandleMaximize fix
more robust transition (better ArgumentException)
Update readme.md
Merge pull request #779 from MahApps/717-punker76-windowstyle-none-blubb-blubb

allow metrowindow to set windowstyle none...