Added cache, changed navigation layout.
Added some background agent support.

Added choose character back
Agent now checks last Update
Updated character picker ui
Removed ChooseCharacter page.  Added chooser
Added error handling for refresh and initial load
Fixed background lastUpdate comparison.

Also added an incomplete notification for summary page. this will be
shown when there is an alert, and a user can press snooze to avoid
seeing alerts for x hours.
Added additional queue information

Fixed alignment issue of skill browser.
Got rid of image extensions.  Using source again

Had a problem with Q42 causing a xaml parsing problem. So since we are
using http anyway for images, source should cache it.