Save/Restore/Sync App State

I'll call this an alpha, here's the status:

Works:
Reopens to last tab / sync open tab over iCloud
Forum cookies sync over iCloud (second+ devices automatically log in)

Hacky:
Favorite forums sync
Expanded forums sync

Tried to implement core data over iCloud, which should be possible.  Encountered lots of issues, will keep trying.  For now, favorite forums and expanded forums sync via the ubiquitous kv store as arrays of forumIDs.  This means there's 2 places a favorite/expanded is defined, which is bad. Hacky, but works, except: expanding a forum on one device sets the forum as expanded on the other, but subforums do not animate in, not sure why.