Fixes #1270
Changed MetroDialogOptions to a DependencyProperty
Removed duplicate DependencyProperty definition.
Merge pull request #1277 from Tide/1270.DialogAccentFix

Fixes #1270
xaml formatting for dialog styles
set mahapps to 0.13.1.0 and resources to 0.2.1.0
0.13.1 release notes
Click on Expander header support
Wording
Now Splitbutton popup closes even when no selection changed event fire (fixes #1295)
Merge pull request #1296 from QuantumDeveloper/Split_DropDownButtons

Now Splitbutton popup closes even when no selection changed event fire (...
Merge pull request #1291 from Dotnetifier/patch-1

Click on Expander header support
Merge pull request #1289 from xxMUROxx/hotfix/Make_MetroDialogOptions_DependencyProperty

Changed MetroDialogOptions to a DependencyProperty