2D graphic library
			------------------


lineh		( color len x y imgbuf -- ) draws horisontal line
		from X,Y coordinates to right, with specified length.
linev		( color len x y imgbuf -- ) draws vertical line
		down, from coordinates X,Y, with specified length.
box		( color x2 x1 y2 y1 imgbuf -- ) draws rectangular
		box. x2 bust be >= x1, y2 must be >= y1.
			x1,y1-----------+
			  |		|
			  |		|
			  +-----------x2,y2

flipv		( imgbuf -- ) flip image vertically.
imgcoltrans	( ImgBuf Color ToColor -- ) Translate all pixels in
		specified image with "Color" into "ToColor".
imgfill 	( color x y imgbuf -- ) Fill image region starting at location
		X & Y with specified color.