improve ASC reader to support xdim/ydim in header instead of cellsize
improve ASC reader to support xdim/ydim in header instead of cellsize

markraz/vtp,markraz/vtp,markraz/vtp,markraz/vtp,seanisom/vtp,seanisom/vtp,seanisom/vtp,markraz/vtp,seanisom/vtp,seanisom/vtp