jsub: provide a sane default email address

By default, qsum mails to $username@$localhost, which hasn't
been a sane thing to do since 1989 at the latest.  This provides
a hardcoded sane default (although users would be best advised
from providing one explicitly).

(Bump package to 1.0.4)

Change-Id: Icb50ac0875a2a98a90d08298ac5ed236a76ecd51
jsub: also support -m so that -M is useful.  :-)

Change-Id: I8c59da30d515ce768355392d7dc9fc0e3b2b632c