Signup enhancements.

- Remove unused segue
- Add call to super
Archive/Inbox: Unread layout and other enhancements

- Add lastAction indicator for errors and info in TSThreadViews
- Enable unarchiving and deletion from archive.
- Unread message layout
Messages view fixes

- Delivered tag
- Fix tap to resend recognizer
- Error messages layout

Reviewed-by: @FredericJacobs
Fixing crash in MessagesViewController.