Add message files for the BounceHandler module.
Add a test that checks for correct extraction from non-standard DSNs.
Move the "bounce detected" message into a reply file.
Add descriptions for new bounce-related message files and
their substitutions.
Cope better with empty messages.
Thanks to SRE.
Rewrite to use message files instead of hard-coded English.

(handle_bounce_message)  Compensate for truncated VERP addresses.
  Thanks to Jeff Wasilko.
(parse_dsn)  Cope with DSN irregularities.
  Thanks to Jeff Wasilko.
Allow the "reason" action to be used in the bounce_rules setting.
(_compile_rule, _ck_var)  Bugfix: Allow variables to be used on the
  right side of comparisons.
  Thanks to SRE.
(get_matching*regexp)  Bugfix:  Remove anchors before calling
  Mj::File::search().
  Thanks to Eric Luhrs.
(parse_open)  Bugfix:  Call parse_in() instead of parse_open()
  as needed to allow Mj2 to work with MIME::Tools version 4 again.
(_r_ck_header)  Bugfix:  Initialize the dup_msg_id access variable
  correctly to avoid tickling the tainting bug in perl 5.5 and earlier
  versions.
Wait to load the Digest::SHA module until it is needed.
Thanks to SRE.
Compensate for changes in the MakeMaker installbin routine.
  Thanks to Devin Reade.
Add safe ops for perl 5.8.1 compatibility.
Thanks to Brock Rozen.
Add "List-ID" to the default delete_headers setting.
Add a List-ID header to the rfc2369 template.
Suggested by Roger Klorese.
(copy_file)  If a link was requested and the Mj2 and CGI directories
  occupy different partitions, use a symbolic link.
  Thanks to Eric Sorenson.
Add an introduction to shell hooks.
Refer to the new shell_hook help file.