Log Message:
Update to 2.4.0beta5.

 2.4.0beta5 (development)

    * Close button was added to the address book dialog, and the layout was
      improved.
    * The automatic junk mail filtering on IMAP4 was enabled.
    * Automatically filtered IMAP4 messages are also counted for new mail
      notification now.
    * The default directory of the printing dialog became the document
      directory.
    * The crash on some environments when verifying signed messages was fixed.
    * The crash on exit when the order of summary columns were modified by
      DnD was fixed.
    * The wrong handling of quotation in multi-byte strings on MIME header
      encoding was fixed.
    * Win32: The bug that the timeout on receiving and sending didn't work
      was fixed.
    * Win32: The path separator problem of folderlist.xml was fixed.
    * Win32: libcairo-2.dll, libgpg-error-0.dll, libgpgme-11.dll, GLib and
      GTK+ was updated to the latest version.
    * Win32: The redraw of windows became smoother (GTK+).
    * Win32: Win32 shell icons are now displayed on the file selection dialog
      (GTK+).