add ipmi barclamp engine structure
Correct parent class of barclamps_controller in ipmi
Merge pull request #38 from waynepallen/pull-req-master-a12ea091bfb90630117f1d475262cf1a10c1c39b

https://github.com/crowbar/barclamp-ipmi/pull/38

Merged by devtool for VictorLowther