Log Message:
Update to 2.4.7:

* The bug that 'Set display item of summary...' button in the common
  preferences dialog always show send folder setting was fixed.
* The previous focus is kept when separation of view is changed.
* The status label is automatically resized now when there is not
  enough width.
* The bug that virtual folders were not sorted properly was fixed.
* The crash when trying to use ascii-armored PGP encryption was fixed.
* The most of compiler warnings were removed.

Changes for 2.4.6:

* The 'To' column was added to the summary view.
* In Sent, Draft, and Queue folders, the 'To' column is displayed by
  default.
* The display column setting of send folders became independent from
  normal folders.
* The ascii-armored PGP encryption was fixed.
* The combined method is used now when both PGP encryption and PGP
  signing are specified.
* The PGP passphrase dialog was disabled on filtering and query search.
* The new message notify will be blocked when a new message is read
  on receiving.
* 'LIST "" "*"' command is used instead of 'LIST \ 
"" "%"' to obtain
  folder list from IMAP4 server.
* The bug that noinferior and noselect flags were ignored until rebuilding
  folder tree when a new folder was created on IMAP4 server was fixed.
* If attached files become nonexistent on sending, error dialog will be
  displayed and the sending will abort.