Separate models from other Core Data stuff.
Move AwfulForumTreeController to "Data" group.
Extract common UITableView methods to hide extra separators and unstick headers.
Teach AwfulForum about its abbreviated names.
Fix AwfulBookmarksController import.
Rework and rename AwfulThreadListController to AwfulForumThreadTableViewController.

- Extract a generic fetched results controller data source.
- Don't inherit from AwfulFetchedTableViewController.
Xcode junk.
Umbrella header for UIKit and Foundation categories.
Rework and rename AwfulBookmarksController to AwfulBookmarkedThreadTableViewController.

- Extract a nicer superclass as AwfulThreadTableViewController.
- Add UIViewController(AwfulExpandingSplitViewController) to umbrella header.
Formatting.
Fix thread actions showing offscreen from iPhone posts view.
Don't update off-screen table views from fetched results controller data source.
Re-add refresh control, infinite scrolling to thread table views.
Rework and rename AwfulPrivateMessageListController to AwfulPrivateMessageTableViewController.

- Don't inherit from AwfulFetchedTableViewController.
- Delete now-unused AwfulFetchedTableViewController.