title: GridViewColumn content and VerticalAlignment
body: <p>i want to display some information in a listview using the GridView.
  i have several GridViewColumns and everything works fine.</p>
  
  <p>However, want the GridViewColumns content to have a VerticalAlignment (Top in this case) 
  but the gridvewcolumn intself doesnt offer a VerticalContentAlignment dependency property.
  when using DisplayMemberBinding there is also no possibility to supply
  VerticalAlignment information.</p>
  
  <p>When using a custom DataTemplate as Celltemplate, i can add a VerticalAlignment="top" dp to e.g. some textblock. however this does not work.
  is there any "nifty-grifty special magic trick" to fullfill this tasK?
  (</p>