I've updated the modemd package to do ttyaction, but it also does it on
mpool too, which is wrong (but not easy to fix, since they use the same
routine to prep a tty). I guess I could add another parameter. Anyway, I
don't use mpoold, so I don't care :-)

(Really it'd be nice if we could add similar functionality to our
getty...)

The URL in the PR is the same.