Can now specify animation options when showing/hiding custom in-window metro dialogs
Closing a tab doesn't work under specific circumstances

When `MetroTabControl.ItemsSource` is bound to a list of `MetroTabItem`s, then closing a tab doesn't work. Currently the code requires that the bound items are not their own container.
Merge pull request #1639 from thoemmi/patch-1

Closing a tab doesn't work under specific circumstances
Merge branch 'pr/1612'

Conflicts:
	MahApps.Metro/Controls/Dialogs/DialogManager.cs
Removed regions and unused usings
Use a generic EventHandler instead of a delegate
Mahapps -> MahApps
Update 1.0.0.md