* wl-vars.el (wl-reply-hook): Abolish.
(wl-draft-reply-hook): New hook.
(wl-summary-reply-hook): Ditto.
(wl-draft-forward-hook): Ditto.
(wl-summary-forward-hook): Ditto.
(wl-draft-kill-flags): New variable.
* wl-summary.el (wl-summary-mark-as-answered-region): Use
wl-summary-set-persistent-mark-internal.
(wl-summary-sync-marks): Use elmo-preserved-flags.
(wl-summary-update-persistent-mark): Make it interactive.
(wl-summary-set-persistent-mark-internal): New inline function.
(wl-summary-mark-as-answered): Use it.
(wl-summary-mark-as-unanswered): Ditto.
(wl-summary-unset-persistent-mark): New function.
(wl-summary-set-persistent-mark): Ditto.
(wl-summary-reply): Don't set answered flag;
Run wl-summary-reply-hook instead.
(wl-summary-forward): Call wl-draft-forward with number.
Run wl-summary-forward-hook.
* wl-highlight.el (wl-summary-persistent-mark-face): New face.
(wl-highlight-summary-line-face-spec): Use it as a default
persistent mark face.
* wl-draft.el (wl-draft-forward): Added optional argument number;
Set wl-draft-parent-number; Run wl-draft-forward-hook.
(wl-draft-reply): Run wl-draft-reply-hook instead of wl-reply-hook.
(wl-draft-kill): Use wl-draft-kill-flags.