Rework of 'query-bulk' implementation for 0.9.x

Please see issue #378, I just reworked for latest 0.9.x branch and made configurable. Corresponding change for carbon was merged by @mleinart while ago - https://github.com/graphite-project/carbon/pull/132
Replacing #824.
Merge pull request #850 from deniszh/0.9.x_query_bulk

Rework of 'query-bulk' implementation for 0.9.x