If nml directory is empty, print legible error
Debug GEOS input directory

If the GEO_INPUT_PATH variable is incorrect, it was hard to debug. Now,
write out full filename to terminal so user can diagnose problem.
Fixed comment statement on last commit
Updates to allow creation of ICON files

Initial condition files can now be created by defining an "XCON"
environment variable as 'ICON'. Code still defaults to producing
boundary files though this can be forced through XCON='BCON'