Log Message:
Update grepmail to 5.30.  Now requires p5-Mail-Mbox-MessageParser>=1.20.

New in version 5.30:
- Updated t/recursive.t to work better when there are version control
  directories in t/mailboxes/directory.
- Updated t/invalid_mailbox.t to be more robust.
- Fixed a bug in t/invalid_mailbox.t for Solaris.
- -F now works again
- Changed incorrect "-h" to "--help" in two error messages.
- Now correctly handles DOS-style line endings in mailboxes.
- Changed single dates so that they are treated as inferred spans, instead of
  a single day. For example "2004" now means "between Jan 1 2004 \ 
and Jan 1
  2005" instead of "between Jan 1 2004 and Jan 2 2004".