[GRASS5] r.statistics workaround for "min" and "max"

[Glynn Clements]

Crudeli wrote:

> r.statistics method=min
>  and
> r.statistics method=max
> 
> seems to work only for the first category of a map.
> I'm working with a landuse map and a DSM (as cover). 
> 
> r.statistics  base=landuse cover=dsm method=min output=landuse.height
> 
> produces a map with the min of a single landuse type (the one with 
> category "1").

Almost the same bug as before; r.stats is being called without the
"-n" flag. As soon as r.statistics sees the first asterisk (indicating
NULL), its parser terminates.

Adding the "-n" in o_min.c and o_max.c appears to fix the problem.

-- 
Glynn Clements <glynn.clements at virgin.net>