MahApps/MahApps.Metro — pull request #342 by Galdoren (2013-02-10 02:33:34+00:00)
Title: TabControl's TabItem's Header margin can be set by the user

The TabControl's TabItem's headers can be moved now, while keeping the
margins of the TabControl's same.

http://img560.imageshack.us/img560/8996/54558293.png