Feature request: limit `how-many' to contents of the region

[Alex Schroeder]

GNU Emacs 20.7.1 (i386-*-nt4.0.1381) of Tue Jun 13 2000 on buffy

Function how-many should work like replace-string in respect to the
following (quoted from the replace-string documentation):

    In Transient Mark mode, if the mark is active, operate on the
    contents of the region.  Otherwise, operate from point to the end
    of the buffer.

I used how-many to count the recipients of a mail by counting the `@'
characters in the To: header.  Unfortunately I was unable to limit the
counting to the region.

Alex.