git-svn-id: https://svn.perl.org/qpsmtpd/trunk@735 958fd67b-6ff1-0310-b445-bb7760255be9
and unique session naming support based roughly on patch from pjh. git-svn-id: https://svn.perl.org/qpsmtpd/branches/0.3x@609 958fd67b-6ff1-0310-b445-bb7760255be9