Merged from Debian.
I think what this actually deals with is the case where gpg is installed,
but gpg-agent is not, since Utility.Gpg.stdParams enables --use-agent
when GPG_BATCH is set, and the test suite enables GPG_BATCH. So, test suite
will work with gpg not installed, or with both gpg and gpg-agent installed,
but not with only gpg.
For this reason, I've also put in an explicit dep on gnupg, although
dpkg-dev recommends it and all debian package builds tend to have it
available implicitly.
aee9adbadc