Fix for bug 154008: some basic (but incomplete) maintenance on bug_email.pl, also fixes a possible security hole with a misuse
of a system() call.
Patches by Erik Anderson <erikba@teamworkgroup.com> and Brad Baetz <bbaetz@student.usyd.edu.au>
r= myk, justdave

bugzilla_email_append.pl calls processmail.pl after writing out the changes.

1. BugzillaEmail.pm is a (kinda, sorta) module which is going to hold the various code which is common between all the scripts which access bugzilla via email.

2. bug_email.pl uses this module

3. bugzilla_email_append.pl is a mostly ready script which will append messages to existing bugs.