[ESS] show wd in mode-line?

[Stephen Eglen]

>
> What ESS can potentially do, is to reset on idle time the emacs's wd to
> that of R. I guess, this would be useful in general, and is pretty easy,
> as ESS has to synchronize some other stuff as well. So if there are no
> objections, I will implement that.

Have a look at `ess-dirs' bound to M-RET -- doing it in idle time could
work, but never bothered me enough.

S