Fix DataContext for ContentControl.

Perspex.Controls/Presenters/ContentPresenter.cs

@@ -94,6 +94,7 @@ namespace Perspex.Controls.Presenters
                     templatedParent = templatedParent.TemplatedParent as TemplatedControl;
                 }
 
+                result.DataContext = content;
                 result.TemplatedParent = templatedParent;
                 this.AddVisualChild(result);
             }