Add node status to API object.

@smarterclayton @lavalamp I'm not sure if this is enough to get it work.  Beat me up.  

 @smarterclayton Should I also take care of v1beta3?

This new status field is fine, but FYI:

We're trying to move our internal representation towards v1beta3.  

There should eventually be just TypeMeta, ObjectMeta, NodeSpec, and NodeStatus in Minion/Node. 

NodeResources was added to the wrong place in v1beta3 and HostIP was apparently dropped (not sure whether that was intentional or not).