GnuPG 2.0 and 2.2 incompatibilities

[Jonathan Perkin <jperkin%joyent.com@localhost>]

I'm not sure whether this affects anyone else, but as the GnuPG
developers have, in their infinite wisdom, made the gpg-agent program
incompatible between 2.0 and 2.2, it is no longer possible to use the
agent to sign packages across multiple branches since 2017Q3.

To work around this I have imported a gnupg20 package into
pkgsrc-joyent based on the last 2.0.30 version we had in pkgsrc, with
a few minor cleanups:

  https://github.com/joyent/pkgsrc-joyent/tree/master/gnupg20

If anyone else is affected by this, let me know and we can discuss
bringing this back into mainline pkgsrc.

Thanks,

-- 
Jonathan Perkin  -  Joyent, Inc.  -  www.joyent.com