Ignore *.swp.
Update README
Separate users and forwards.

Users now have one forward_destination, and no forward may use the name
of a user in the source.

We temporarily lose the possibility to forward user-messages to multiple
destinations until we find a way to validate multiple concatenated
addresses in User#forward_destination.
Confirm destroy without JS.
Use bootstrap-sass and obsolete JS completely.
Use rails 3.2.11.
Styling and refactoring of forms.
Validate uniqueness of name for Domain, User.