sync with mail/mutt.
- Update the maildir header cache to the current version.
- Update the threadcomplete patch (including some documentation on it).
- Beautify the documentation in some cases.
- Correct the note how to get SLANG working.
- Bump PORTREVISION.
PR: ports/71103
Submitted by: maintainer
threads via "T ~a" (means: tag all entire threads where at least
one message of the tread is tagged).
o Bump PORTREVISION.
PR: ports/54361
Submitted by: Udo Schweigert <udo.schweigert@siemens.com> (maintainer)