title: Horizontal stretching - group header ListView
body: <p>So... Any bright ideas how we can enable Horizontal content stretching on the GroupHeader template of a Grouped ListView in Win RT - phone?</p>
  
  <p>I'm all ears!</p>
  
  <p>I've added a demo application so you can try it out - please do before posting your answer!
  Code can be found here <a href="https://github.com/Depechie/ListView-HorizontalStretch-RT81" rel="nofollow noreferrer">https://github.com/Depechie/ListView-HorizontalStretch-RT81</a></p>
  
  <p>I added 2 pages, MainPage has the problem of not having Horizontal stretching.
  MainPage2 has a fix for Horizontal stretching, but because of that fix, the JumpList ( zoomed out view ) is not working anymore.
  You can navigate from MainPage to MainPage2 through the appbar button.</p>
  
  <p>Here the 2 visuals</p>
  
  <p><img src="https://i.stack.imgur.com/6xxPS.png" alt="enter image description here">
  <img src="https://i.stack.imgur.com/dTvYW.png" alt="enter image description here"></p>