Remove vestigial burst buffer config params

Now that the TRES logic is working, remove vestigial burst buffer
  configuration parameters: JobSizeLimit, UserSizeLimit, PrioBoostAlloc,
  and PrioBoostUse.
Also remove the PrivateData configuration parameter and use a Flag
  value of PrivateData instead.
Stop printing a bunch of configuration parameters that are not
  applicable to the cray plugin (e.g. CreateBuffer script).