Merge pull request #822 from deniszh/0.9.x

Fixing safe pickles list to making remote rendering work. Fixes issue #608
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