Now risk calculations require the hazard_job_id, not the hazard_calculation_id
Added the option --hazard-job-id
Now the ProbabilisticEventBased demo uses the new feature
Removed the obsolete option --hazard-calculation-id
Merge pull request #1508 from gem/hazard_job

Introduced --hazard-job-id and made it possible to reuse exposures imported in the hazard part of the computation