Log Message:
Fixes PR pkg/49166

Contributed by: Leonardo Taccari <iamleot@gmail.com>

Update mail/nmh to 1.6.

Changes:
The biggest changes in this release are in the arena of MIME handling.
Specifically relating to MIME composition and display.  On the
composition front, mhbuild(1) will now automatically be run by send(1)
for all drafts.  Specifically, mhbuild is now run with the new -auto
flag, which will suppress the processing of mhbuild directives and cause
mhbuild to silently exit if the draft is already MIME-formatted.  When
invoking mhbuild manually via the "mime" command at the WhatNow? prompt,
mhbuild will behave as before and process mhbuild directives.

In both cases (automatic and manual invocation) mhbuild will encode email
headers according to RFC-2047 rules.  Mhbuild also will use RFC 2231
encoding rules for MIME parameters when appropriate.  In addition, the
attach system has been substantially reworked; the new header name is
now "Attach" (to better align with other MUA behavior) and cannot be
changed by the end-user.  The existing "attach" command simply adds
the filename(s) to the draft in new Attach: headers, and the actual
file processing is done by mhbuild; this attachment processing will
take place in either automatic or manual mode.

On the display front, mhshow(1) will now automatically convert text
into the user's native character set using iconv, if nmh was built
with iconv support.  Also, mhshow will now by default only display
text content that was not marked as an attachment.  By default all
displayed content wll be run under one pager, as opposed to individual
pagers for each part as was in the past.  Non-displayed parts will be
indicated using a marker string, which can be customized by a new
mh-format(5) string.

All nmh utilites now understand RFC 2231-encoded MIME parameters and
will automatically convert the encoded parameters into the native
character set, when appropriate (again, assuming nmh was built with
iconv support).

In other changes, sequence files are now locked using transactional
locks: locks that are held across sequence file reading, modification,
and writing.  The locking algorithm used for spool files and nmh data
files is now runtime configurable.

For people that struggle with mh-format(5) files, a new utility for testing
them has been developed: fmttest(1).  It includes the ability to trace the
execution of format instructions.

For users that wish to use Unix utilities on their mail, a new utility
to transform MIME messages to more easily-digestable format is now
available: mhfixmsg(1).  It supports a number of options to control
the message transformation.

For users of spost(8), the support for spost has been rolled into post(8)
under a new sendmail/pipe MTS.  A shell script emulating the old behavior
of spost has been provided.