Line detection and extraction

Normal classes:

PixelMapC	Binned hash table of pixels in an image.
PixelMapSearchC	Pixel map search base class.
PCIndex2dC	Pixel near parametric curve.
PCPixelListC	List of PCPixels.
PCPixMapC	Simple mapping between a curve and some pixels.
PCPixMappingC	Mappings from a curve to a set of pixels.
PPHoughTransformC	Progressive Probablistic Hough Transform.

Normal functions:

operator <<(ostream &,const PCPixMapC &)
operator >>(istream &,PCPixMapC &)	Mappings from a curve to a set of pixels.
operator <<(ostream &,const PCPixMappingC &)
operator >>(istream &,PCPixMappingC &)

Develop classes:

PixelMapSearchBaseC	Pixel map search base class.
PPHoughTransformBodyC	Line segment extraction engine.