Add additional options to Mutt output

Incorporating an extension by Fernando Schapachnik which adds options
to Mutt output for using addressees' nick names instead or additional
to Mutt aliases.

FEATURE: 274937
CCMAIL: fernando@schapachnik.com.ar
DIGEST: Users who use kabcclient to access KDE's address book from Mutt
can now get a contact's nick name (if it exists) instead of or
additional to the usual alias key.

E.g. if there is a contact John "Jonny" Doe <j.doe@example.com>
the instead of

JohDoe John Doe <j.doe@example.com>

one can now get either (new option 'prefernick')

Jonny John Doe <j.doe@example.com>

or (new option 'alsonick')

JohDoe John Doe <j.doe@example.com>
followed by
Jonny John Doe <j.doe@example.com>