[Nmh-workers] Features for 1.6

[Ken Hornstein]

So it's been more than a year since the 1.5 release ... and I'm thinking
it's time to start working on 1.6.  I think that 1.5 holds up pretty
well so I'm not itching to get 1.6 out of the door right now, but there
is some cool stuff in the master branch that would be nice to get out
there.  But I still want to get some things in there, so here's what I
was thinking about getting working for 1.6.

- Support character set conversion for mhshow(1) using iconv
- Adapt meillo's changes to mhshow(1) so each MIME part doesn't use their
  own pager.
- Maybe make mhshow(1) the default instead of show(1).
- Always run mhbuild on outgoing drafts.
- Have mhbuild handle RFC-2047 encoding
- Support RFC 2231 MIME extended parameter encoding and decoding

And to borrow a management term, some "stretch" goals are:

- Support the composition and display of format=flowed messages.
- Add encryption/decryption support via external programs (like openssl,
  gpg, etc).
- Design a proper MIME multiplexing architecture that can handle things like
  having repl decide which MIME parts to select from a message to include in
  a reply.  Maybe via mhl?

Anything else that strikes people's fancy?  Obviously preference will be
given to items that include coding resources :-)

--Ken