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


Former-commit-id: 11c3d9b5a4aca4f3e9f04eb82e496de241b5120a [formerly d5932c79f98939bacdd0835a4a730ec614b922a6]
Former-commit-id: 93f47bf15d876f7c509c7983685c7998bc426112
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine