Update the widget previews to the new icon color

The numbers in the preview snapshots (debugging aid) were:
00:05 mdpi, 00:06 hdpi, 00:07 xhdpi, 00:08 xxhdpi

Now:
00:15 mdpi, 00:16 hdpi, 00:17 xhdpi, 00:18 xxhdpi
Update to buildTools 21.1.1
Color the action bar firey red (Material Design style)
Hide the options menu

Restore it when it contains something useful.
New screenshots for the Play store.