[GRASSLIST:3141] export the monitor

[michele.rocc@libero.it]

Hi, 
I was looking for a function for  exporting in a raster image (ppm,tiff
or anything else) the aspect of a graphycal monitor "as it is".
This because i need to merge more rasters file.
I tryed with r.patch but (maybe because i don't use it properly) it
conforms all the rasters generated with s.to.rast to a single color.

thanks,  Michele.