bug#2269: 23.0.60; ambiguity in info file

[Juri Linkov]

> I'm often trying to count lines in a region in dired and
> I very rarely use dired-backup-diff as I use version control and that
> function doesn't use vc and therefore I get an error on M-=.

Thanks for the suggestion.  Now this is fixed so that `M-=' is not bound to
dired-backup-diff, and the global `count-words-region' is in effect in Dired.