debug symbols for package pprepair

 pprepair (planar partition repair) takes a set of polygons and ensures that
 they form a valid planar partition, made of valid polygons and having no gaps
 or overlaps. It can be used as a validator, telling of problems in individual
 polygons or in the planar partition, and also as an automatic repair tool,
 outputting a set of polygons that do form a valid planar partition.