Log Message:
- Update to sylpheed-2.5.0.
- Add patch from Fedora which makes the gtkspell option build again, with
  the enchant-backed gtkspell.
- Add DESTDIR support, from mail/sylpheed-devel

Changes from 2.4.8
* New features
  o The vertical 3-paned view mode was added.
  o The feature to save SSL peer certificate was added.
  o The option 'Treat HTML only message as attachment' was added.
  o The feature to confirm missing attachments was added.
  o The feature to confirm recipients before sending was added.
* Feature improvements
  o To: header is also searched by quick search in Sent/Draft/Queue folders.
  o 'Edit/Quick search' menu was added.
  o Spaces in address and server entries on account preferences dialog are now
    automatically removed when applied.
  o The compose window now remembers the maximized state.
  o The focus will not move from the text view to the summary view with
    'Next/Prev' keyboard operation now.
  o The alert dialog is displayed now when PGP signing/encryption failed.
* Bugfixes
  o The bug that caused busy loop when initial connection was immediately
    refused was fixed.
  o The bug that the quote description dialog never appeared again after closing \ 
it with the close button was fixed.
  o The new/unread status display on quick search filtered mode was fixed.
  o The windres command will not be enabled on non-win32 platforms now.
  o The address completion was fixed.
  o Win32: --attach option was fixed.
  o The sylpheed.desktop file was fixed.
  o A crash bug was fixed.
  o Content-Transfer-Encoding header with comments was supported.
  o UTF-8 locale strings with suffix '.utf8' were supported.
  o The 8KB restriction of template body size was removed.