Change MailMessage.validateFrom() to respect internal proxy hosts.

The online server was getting `ORIGIN: "<bridges@ponticum>"' for the
`origin` parameter to bridgedb.email.server.MailMessage.validateFrom().
In order to automatically allow forwarded emails from localhost, we
passthrough on the first check on canonical domains in the
validateFrom() method if the domain matches the one returned from a
socket.gethostbyname() or socket.gethostname(), otherwise we fallback to
canonicalizeEmailDomain() later.
Fix Python2.7.3 UnicodeDecodeError in MailMessage.getIncoming().
Fix GnuPG invalid armor header in email.templates.getFooter().
Fix GnuPG 'invalid dash escaped line: --\n' error in templates.getFooter().
Whitespace fixes in lib/bridgedb/email/server.py.
Whitespace fix for one line in scripts/make-ssl-cert.
Fix scripts/make-ssl-cert to use `exit 1` after wrong number of args.
Hush OpenSSL during key/cert creation in scripts/make-ssl-cert.