#2 defcustom mc-default-scheme

[Peter S Galbraith]

After switching from PGP to GPG, I found mailcrypt no
longer worked, so I went searching for a variable to
set to tell it to use GPG instead and hacked in:

(setq mc-default-scheme 'mc-scheme-gpg)

I later found this in the docs:

(mc-setversion "2.6") ; for PGP 2.6 (default); also
"5.0" and "gpg"

It might be more user-friendly to use a defcustom for
mc-default-scheme and have an mailcrypt menubar entry
for "Customize mailcrypt".

Alternatively (or additionally), use a default of nil,
and if the user hasn't customized it by setting the
variable, then use 'executable-find' to search for the
pgp or gpg commands on the system.

Thanks,
Peter Galbraith <psg@debian.org>