Now all classes and members are either exposed to bindings or marked
as "not available in Python bindings" in the docs.
Drop test thresholds to 0. Now it should be much easier to determine
what missing members have been added which are causing test
failures.
Split length from perimeter calculation in geometry API, as
returning perimeter for length for polygons is misleading and
results in incorrect length/perimeter calculations for mixed
geometry collections.
Enable length & perimeter unit tests against reference geometries.
Now the length & perimeter values match those calculated by
PostGIS.
