[evolution-patches] 271894, pgp encrypted message attachments fail

[Not Zed <notzed novell com>]

See patches on here:

http://bugzilla.gnome.org/show_bug.cgi?id=271894

I also noticed the inline pgp code was in the wrong class, so i
re-arranged it.

And fixed the error messages - awaiting i18n team approval on those,
otherwise i'll drop back to the innacurate smime one.