[9front] marshal(1) and pgp

[chris@chrisfroeschl.de]

marshal(1) advertises the -pe and -ps flags to encrypt/sign the input.

The flags are indeed implemented (/sys/src/cmd/upas/marshal/marshal.c:389) using
a /bin/pgp (/sys/src/cmd/upas/marshal/marshal.c:1171) .

Does anyone know what this pgp exec is? Some historic relict?

I'm only aware of moody's https://github.com/majiru/pgp .

I see three options:
1. Remove those flags since there is no real standard pgp
2. Define/Ship a standard pgp for 9front
3. Move pgp logic into it's own more independent component
	to be piped or offered through the mail client
	(like an extra nedmail option or something like that)
	(a better architecture?)
	
I would work out a patch if an appropiate solution is found.

I'm currently using moodys pgp with a patched marshal. Regarding 2.,
I don't think that the golang pgp implemenation would really fit into
the 9front release, since this would be the first golang project to
be part of the standard build.

Feel free to comment.

chris