Log Message:
Update squirrelmail pacakge to 1.4.20.

Version 1.4.20 - 06 Mar 2010
---------------------------
  - Fixed issue with search not using literals correctly (#2846511).
  - Fixed issue with returning to search results due to new security token
    code.
  - Fixed issue with multi-part related messages not showing all attachments
    (#2830140).
  - Fixed for security token missing in newmail plugin (#2919418).
  - Fixed sort in Sent folder to sort by "To" field instead of \ 
"From" field
    (#2907412).
  - Fixed mailto: urls containing + characters.  Thanks to Michael Puls II
    for the patch.
  - Made base URL autodetection more robust; fixes some lighttpd issues
    (probably #1741469).
  - Encoded From headers are now properly quoted (#2830141).
  - Multibyte strings (notably subjects) are now handled correctly (#2824813,
    #2925731).
  - X-DNS-Prefetch-Control: off header is now sent to browsers to prevent
    information leakage when Firefox does DNS prefetching for URLs contained
    in emails.
  - Added unread links in message view.
  - Added the ability to configure Google Mail (Gmail) as the mail server
    behind SquirrelMail.
  - Added option in display preferences that allows the signature to be
    stripped from the original message when replying (#2952876).  Thanks to
    Sven Strickroth.