0.24
	Added arc_2pt function.

0.23
	Changed isleft() function to howleft().

0.22
	Fixed shift_line() to properly use $distance
	Changed pgon_centroid calculation.
	Added foot_on_line() function.
	Added stringify_line() function.

0.21
	Several new functions and features.

0.20 
	Added sprintf("%0.9f") to seg_seg_intersection()