Bug 851270: Re-enable purging on try. r=bhearsum
nobug: Add nextSlave functions to mozharness builders. r=bhearsum
Bug 974140, release builds not using space requirement of platform config, r=rail
bug 972415:  Intermittent Linux spot builder "command timed out: 1800 seconds without output, attempting to kill" while trying to install mock. r=bhearsum
Merge bugs 851270, 974140, and 972415 to production.

--HG--
branch : production-0.8