Cleaned up exit codes.
Cleaned up exit codes.


Former-commit-id: 25e8ebc905dec4b6cf9567a63ebdb1e32a9e98bf [formerly eaf85151e6c09d4496fd98ed6e16125ed831c538]
Former-commit-id: d41aed8face5c782b7e31de55929413c707c0bed
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine