More Prepping!

- Added design tool check for logoutcommand
- Added something special to the About panel
- Added hook for viewing arbitrary urls in ThreadDetails.xaml
- PagedListViewModels will now refresh the UI on appending, even if
nothing was appended.
Forum Layout Update Fix

Fixed an issue on the HomePage where incorrect forum headers appeared
for the wrong forums.
Removed Location Feature

- Not needed.
2.0 Release Tag
Page Nav Fix; Marketplace Stuff

- Fixed an issue where jumping to the first or last page of a thread
desynchronizes the navigation stack.
- Removed old app icons, added new ones.