Remove AwfulForum.expanded property.

I'd somehow missed this property in my earlier crusade to remove all user data
from Core Data. I took the opportunity to clean up some bits of the forums list
controller too.
Implement and use basement view controller on iPhone.
Random Xcode whatever.
Set project class prefix to 'Awful'.
Fix copyright header.
Update code sign identity and provisioning profile.
Put new app icon and iPhone launch image into asset catalog.