[GRASSLIST:10689] Are negative values acceptable for r.cost?

[Patton, Eric]

I've just finished reading a past thread on r.cost execution time (see
GrassList #7781) and I was wondering if r.cost suports negative DEM values
now/yet? This would be very helpful for cases where bathymetry DEM's are
used, for instance - all z values are always negative.

~ Eric.