Log Message:
Update to Exmh 2.7.2:

* 2.7.2 More bug fixes, plus some performance improvements for the new
        sequences code added in 2.6. The exmh-strip utility is integrated as
        "Save/Extract Attachments".
* 2.7.1 (Wasn't officially released in tarball form.)
* 2.7.0 Accumulates over a year of minor fixes in the CVS tree.

Also fix some pkglint complaints, and take maintainership.