Sets whether a gml:boundedBy element should automatically be generated and included. The
element will not be updateable, and is simply derived from the geometries present in the
feature.
Note that the setGmlPrefixing() interacts with this occasionally, since it will
hack in a gml prefix to a boundedBy attribute included in the featureType. If gml prefixing
is on, and featureBounding is on, then the bounds from the attribute will be used. If gml
prefixing is off, then that boundedBy attribute will presumably be in its own namespace, and
so the automatic gml boundedBy will not conflict, so both will be printed, with the automatic
one deriving its bounds from the boundedBy attribute and any other geometries in the feature