"Can't connect to node" with every ping failure.

Changed the logging level of a few other message.

until the previous one completes. This avoids having too many cycles
active (and a bunch of threads too). Ping_nodes control functions moved
to a new module.

reportted in log (via #define PRINT_TIMES). Resolution of time stamps
changed from 10msec to 1usec by changing to gettimeofday instead of clock.

   print_exit_status

allocated/idle.

 o Call waitpid with WUNTRACED to report on stopped processes.

instead of REQUEST_KILL_TASKS RPC to slurmd.

memory. Minor code restructuring (moved setrlimit into _init_config()
function from main).

Set "reason" field when node set down for slurmd error.

request.

the backup controller and proc_req.c is the code to process incomming
RPCs. No changes in controller logic were made for this.
job_mgr.c was also modified to better handle bad job records on
controller restart's data recovery.

  - Enhanced xsignal.[ch] to more easily block and unblock sets of signals
    [ added: xsignal_unblock xsignal_sigset_create, changed: xsignal_unblock ]
  - Take advantage of above changes in srun and slurmd code
  - Only unblock signals that were specifically blocked in slurmd
    (instead of *all* signals) when exec'ing user tasks.

 o allow error() to return SLURM_ERROR so callers can do:
     return error (...);

state. Bug was resulting in update of node going to DRAINING instead
of DRAINED from DOWN state.

large job specifications

function.

particularly for the get_info RPCs.

 o slight code format improvements