export/hazard:
export/hazard:

Slightly faster and slightly leaner (less memory usage) query for hazard
curve export.


Former-commit-id: 7d2563867c37c3f9a04a66091d097dced72f1b47 [formerly c63662df021a6e6ced81d8e9b82732a9490eca68]
Former-commit-id: a9c51bbc18e036367041f1c69752e5c670ecafc0
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine