LEVEL1 saxGML4j GML filter: Sends basic alerts for GML types to GMLFilterGeometry.
This filter separates and passes GML events to a GMLHandlerGeometry. The main simplification
that it performs is to pass along coordinates as an abstracted method call, regardless of their
notation in the GML (Coord vs. Coordinates). This call turns the coordinates into doubles and
makes sure that it distinguishes between 2 and 3 value coordinates.
The filter also handles some more subtle processing, including handling different delimiters
(decimal, coordinate, tuple) that may be used by more outlandish GML generators.