added a function that releases hazard curve data from the kvs
added a function that releases hazard curve data from the kvs


Former-commit-id: ee4bf5e5fda79d6d518e8143f9bdec6bf3cb1ed7 [formerly e73e0ee61bdc8743a3be69aefbfc64b985ee3ce0]
Former-commit-id: 8139fbc15abc1b05c445ad129ef58f81fd323119
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine