more consistent and DRY access to job params
more consistent and DRY access to job params


Former-commit-id: 0413a2e398eb4602f2bcc0584e36994bff507f95 [formerly 88a33e87340d5f57baec400787d556b6cf6b8405]
Former-commit-id: 9af8eecb40758fdf155a5577ac2534042e6c6d1a
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine