This is at least easier to understand than the magic hash. It may also
be a bit more robust, although it is hard to imagine these numbers
changing without many other changes in git.
This should be more robust with respect to tags with whitespace and
and other special characters. It also (hopefully) fixes a remaining
bug handling message-ids with whitespace. It should also be
noticeably faster for large sets of changes since it does one exec per
change set as opposed to one exec per tag changed.
This should make nmbug tolerate tags with whitespace and other special
characters it. At the moment this relies on _not_ passing calls to
notmuch tag through the shell, which is a documented feature of perl's
system function.
There seems to be consensus to use presence in contrib as
documentation of limited support by the notmuch developers; in fact
nmbug is pretty integrated into our current development process, so
devel seems more appropriate.