geometric -- polygon testing and refurb

[Fred T. Hamster]

polygon:

1. test polygons against others:
   1. try rectangle's inside method against polygon.
   2. try an approximation of a circle also.
   3. also ellipse maybe?
2. but definitely test all the objects that provide inside() and see if the polygon agrees with that.
   1. Implement polygon class to add into geometry. Support open or closed types, with sequence<point>. Should use the inside method of kevin's.
   2. Use polygon class to implement still unimplemented inside routines in the geometry library (like in triangle).