calls for proper pthread syntax

  suspend times accumulated prior to a job requeue/restart

higher priority job

  depending upon PreemptMode configuration

  which is the proper data type for this function

Add PreemptMode-checkpoint (needs more testing).

    that the select/cons_res plugin has allocated to a job.

  what the CPUs mask represents

nodes in "scontrol show job" into just one line.

rename _cr_priority_selection_enabled() to _job_preemption_enabled()
add _job_preemption_killing()
add limited support to avoid counting memory allocated to nodes by 
  jobs that are going to be killed or requeued as part of the process
  to start a high-priority job