added the feature to reply to attached message/rfc822 messages.
implemented printing of MIME part. Code cleanups.
implemented 'Save all'.
reimplemented MimeView with GtkTreeView.
changed the implementation of switching Text/MIME view.
save selected attachments if mimeview has focus when 'File/Save as...' is selected.
improved MimeView and file selection dialog.
Initial import of Sylpheed (GTK2 version).