[CDF-372] - CCC - The new pointing mode, "near", is not working satisfactorily
* Added internal methods for handling float comparisons, that are precision errors aware(pv.epsilon, pv.floatLess, ...)
* Changed pv.Shape methods that make comparisons to use the new float methods, to kill some experienced floating point error related bugs.
* Added mark-static property pointingRadiusMax to allow limiting the pointing distance per mark.
* Fixed bug in pv.Shape.Arc and pv.Shape.Wedge for Arcs with an angle span of 2PI; containsPoint would not work for these Wedges.
* Added bbox method to every Shape type. Generic implementation uses the `points` method.
  The method `points` should return as many points as required for a bbox computation to be correct.
  Changed the Arc and Wedge implementation of `point` accordingly.
* Extended pv.Shape.containsPoint to support a "collapsed" mode.
* Largely improved the point behavior.
Merge pull request #13 from dcleao/CDF-372

[CDF-372] - CCC - The new pointing mode, "near", is not working satisfactorily