node_features/knl_cray fixes from testing

Discovered in testing that the cnselect command only returns information
  about KNL node state for nodes that are already up. If a node is down
  or in the process of booting, only capmc as the state which will be in
  effect when the boot completes. This change merges the old logic (reading
  state from capmc) with new logic (merging new state information from
  cnselect into the capmc data), which results in the most complete
  picture possible about the KNL state.
bug 2850