Revision 2170

Looks like I misinterpreted the specs.

First of all, a <BoundingBox> element does not have to be specified.
This could cause the program to fail if later a bbox will be requested
which wasn't defined in the Capabilities XML.

Secondly, since EPSG:3426 is the implicit spatial reference system for
<LatLonBoundingBox> its values should be returned if the client
requests a bounding box for SRS EPSG:3426, even if no <BoundingBox>
was defined for EPSG:3426.

Therefore whenever a native BoundingBox request cannot be fulfilled,
check whether the requested SRS is EPSG:3426, in which case return the
LatLonBoundingBox values.