added and changed:
isInside	                    in	PSPath
isOnArc 	                    in	Arc.java
isInCircle                  	in	Arc.java
isGoingThroughInterior in  Arc.java
rayIntersect	in	Arc.java

isOnSection	in	LineSegment.java
rayIntersect	 in	LineSegmant.java

pointByParameter in	PSPoint.java