Optimize prepared polygon distance

[dbaston]

The implementation of PreparedPolygonDistance begins with a call to PreparedPolygonIntersects to cover the case where a containment relationship exists between the target and test geometries. However, the segment intersection test performed by PreparedPolygonIntersects is unnecessary. If any segment intersect, they will be found by IndexedFacetDistance.

This PR improves the performance of PreparedPolygonDistance by performing the PIP containment tests directly within PreparedPolygonDistance and avoiding the call to PreparedPolygonIntersects. In the following performance test, which relies heavily on PreparedPolygonDistance, runtime is reduced by 45%.

bin/geosop clusterWithin 1e-3 -t -q -a ~/data/world.wkt

This should bring additional performance improvements to #692.

[dbaston]

This also brings performance of prepared zero-distance check ahead of prepared intersection testing. I think this essentially means IndexedFacetDistance is outperforming MCIndexSegmentSetMutualIntersector for this dataset.

[pramsey]

Good get!