Custom Ellipsis for grid headers
Merge branch 'AppBarGrid' into UI_Overhaul_GridHeaderEllipsis

Conflicts:
	HudlRT/Views/VideoPlayerView.xaml.cs
Updated logic to determine text block size
Added ability to scroll grid with headers back into the video page grid
Merge branch 'AppBarGrid' of github.com:hudl/hudl-win8 into AppBarGrid
Merge branch 'UI_Overhaul_GridHeaderEllipsis' into AppBarGrid

Conflicts:
	HudlRT/Views/VideoPlayerView.xaml.cs
Fixed merge