Switched from old scopes to new scopes
- For models Post, PostAction, Invite, and Topic:
  - Removed after_recover callbacks
  - Added a new method called #recover to replace the equivalent method from
    the acts_as_paranoid gem
  - Where appropriate, removed after_recover callbacks by placing the method
    that would previously have been called at the end of the #recover methods
  - Added default scopes to models in order to replace this functionality from
    the acts_as_paranoid gem
- In other places:
  - Replaced .with_deleted calls to .unscoped calls