* wl-summary.el (wl-summary-mode-map): Bind wl-summary-save-status to

* wl-summary.el (wl-summary-mode-map): Bind wl-summary-save-status to
 `C-x C-s'.
(wl-summary-save-status): New command.
(wl-summary-exit): Don't clean-up temp marks when sticky.
(Applied patch from Nakayama-san [wl: 09548])
(wl-summary-delete-all-temp-marks): Added optional argument no-msg;
Do nothing when no mark data.
(wl-summary-save-view-cache): Copy local variables to the temp buffer;
Call `wl-summary-delete-all-temp-marks' before saving.