Removed inner grid that takes row height=auto because this allowed grid to grow without height restriction. Removed ScrollViewer that contained ItemsControl because this is ignored by ItemsControl and set its ControlTemplate to surround ItemsPresenter with ScrollViewer instead.
Merge pull request #45 from Esri/jenn6286/issue15_MeasureDisplayScrollbarItemsControl

Jenn6286/issue15 measure display scrollbar items control