Should support line styles as in pic:
	dashed(l) (boxes, lines)
		dashes of length l (default .05),
		spacing as close as possible to l
		but with a dash hitting each end of the line
	dotted(l) (boxes, lines)
		dots, separated by as close to l (default .05)
		as possible while hitting both endpoints
	arrow(dir, len, count) (lines, arcs)
		arrow heads ->, <- or <->, default length .1,
		default count 2
	fill(value)	(boxes, circles)
		default fill value is .3