improved MimeView and file selection dialog.
replaced intl.h with glib/gi18n.h.
src/mainwindow.c: removed commented out lines.
use GTK stock button for dialog button set.
restored the resize grip of the main statusbar.
removed support for systems which don't support iconv.
set shadow type of GtkTextView, and don't set border_width of toolbars.
Initial import of Sylpheed (GTK2 version).