[GRASS5] v.in.gns fix

v.in.gns:

#TODO: fix dms_lat,dms_long DDMMSS -> DD:MM:SS

use cut -b1,2

e.g.

IN=DDMMSS
DEG=`echo $IN | cut -b1,2`
MIN=`echo $IN | cut -b3,4`
SEC=`echo $IN | cut -b5,6`
DEG_STR="$DEG:$MIN:$SEC"

Hamish