export/hazard:
export/hazard:

Added util function for organizing exported hazard curve results by
GMPE and IMT.


Former-commit-id: 2eb954d6290c30e32b84f2e9e8fae0b1fe4d7804 [formerly d8e9a2399cf90dd9d8504f21c0f9c7cae47fce82] [formerly d8e9a2399cf90dd9d8504f21c0f9c7cae47fce82 [formerly ba4f475717b2f926c5586a92a67192c1205a0456]]
Former-commit-id: 1d03a1d70eb0a1f4d79c90e13be068c69826c239
Former-commit-id: 2446c3281e7d9d8b295c80ac11e2f6dc19a0d101
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine