o Export SLURM_NODELIST environment var in all cases

 o Changed correspondingly calls to above
 o Removed unnecessary envc member of job structure, along with references
   to said member

    is through with them.
 o added new function unsetenvp() to support above

the old_job_allocation response so as to conform with job step's specification.
For example, remove nodes that are excluded (-x), set the node count to
that requested (-N, eliminate nodes as required), etc. This requires
modifying the node list including the slurm_addr, and cpu_count arrays.

Add new logic to prevent some node state transitions via update_node RPC
(e.g. IDLE to ALLOCATED).

By default, logging is to syslog. Expanded usage description to be more
complete.

without duplicates. For example, we want to convert a users request for
nodes "lx1,lx2,lx1,lx3" to "lx[1-3]".

entry counting function. As a job is completing the bitmap gets cleared
as nodes complete, resulting in incorrect values.

job is scheduled.

required by a pending job. NOTE: On heterogeneous systems or if the
requested number of nodes is a range then the actual number of nodes
allocated may differ from the value displayed.

required by a pending job.

batch_job_launch RPC, then deallocate those resources and requeue the job.
If a node registers and fails to show a batch job that should have a
script running there (node zero of allocation), then consider the job
complete.

"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).