dem_adjust: Fix some subtle issues
dem_geoid: Rename from dem_adjust
dem_geoid: Rename from dem_adjust
dem_geoid: Sanity check for compatibility
dem_geoid: Support Mars, compensate for datum height difference
dem_geoid: Minor touch ups
dem_geoid: Minor
Sessions/DG/XML.cc: Must throw the right kind of exception to catch it later
InterestPointMatching.cc: Catch all exceptions
LinescanDGModel.h: Correct comment
XML: Check for non-zero poly coeffs for optical distortion
dg_mosaic.py: Handle a.b.xml and a.XML in addition to a.xml
stereo: Produce lowres is no longer used in multiple places

Thus produce lowres should no longer be inside stereo.{cc,h}.
gitignore: Update to represent current state of affairs.