Squashed 'MahApps.Metro/' changes from 5509b1c..9a95244

9a95244 Fixed a typo
942671c Finish the 0.14 release notes
732296a introduce version 0.14
60491b9 First iteration on the 0.14 release notes

git-subtree-dir: MahApps.Metro
git-subtree-split: 9a9524465b2e6385d322fd777ce4d19ea06f521a
Merge commit '43eba2a384b6e67c15fd988e59b80dd3c8995d71'
Fix #23: crashes when selected hide menu in tool panel