* wl-util.el (wl-biff-check-folders-running): New variable.

* wl-util.el (wl-biff-check-folders-running): New variable.
(wl-biff-check-folders): Set and check `wl-biff-check-folders-running'.
(wl-biff-check-folder-async-callback):
Set `wl-biff-check-folders-running'.
(wl-biff-check-folders): Enclose `wl-folder-check-one-entity'
with unwind-protect.

* wl.el (wl): Call `wl-biff-start' before `wl-folder-auto-check'.
Enclose `wl-folder-auto-check' with unwind-protect.

* wl-util.el (wl-biff-start) [Emacs19+]: require 'timer.
(toplevel) [Emacs19+]: Removed autoload setting for "timer".