As this code has significant bit-rot and requires a lot of work to compile and
run again, it is currently deactivated.
The test also writes to the files "/Users/jmt/Desktop/airways.kml" and
"/Users/jmt/Desktop/procedures.kml" and would need to be modified to write to a
temporary directory and the file contents reread and checked by the test.
This change is the logical counterpart of SimGear's change from commit
79f869a7f32910197be72b21f6489fbbba02c836 that moved the following files
from simgear/misc to simgear/io/iostreams:
gzcontainerfile.cxx
gzcontainerfile.hxx
gzfstream.cxx (formerly zfstream.cxx)
gzfstream.hxx (formerly zfstream.hxx)
sgstream.cxx
sgstream.hxx
sgstream_test.cxx
* Fixes errors selecting 'nearest' items, including duplicates
* Stable behaviour around the poles and dateline
* Decently efficient, even for 'everything within 500nm' queries
