Move AsPolygonSet out of package file.

Moving AsPolygonSet out of the package file allows us to dodge a
compiler error.
Removed debug path storing code from shortestpath

...and increasing the speed by a lot for large shortest path queries. Got to love free speed boosts.
Merge pull request #533 from joshmarcus/topic/aspolygonset

Move AsPolygonSet out of package file.
Merge pull request #534 from lossyrob/fix/shortestpath

Removed debug path storing code from shortestpath