BMC/IPMI smart proxy actions

This pull request contains everything that is needed to perform IPMI operations on a BMC interface. In order to test this, a smart proxy with the BMC capability should be hooked to foreman. This should facilitate the integration of a console for physical machines in foreman.

A further step down the road would be to merge this and similar actions for virtual machines into something generic. 

After this is merged a host with IPMI enabled (username and password set) and a IPMI SmartProxy available, should look like this https://docs.google.com/file/d/0Bz4WMhz8WLjnaFpzdGFEMEQzY00/edit?usp=sharing