Plus some minor code clean-up with no changes to logic.

for NULL values. Remove redundant code.

 o remove unneeded #include from interconnect.h

Some of this was formerly in slurmctld/read_config.c.

than within slurmd. This means "scontrol show config" shows the proper
value rather than "NULL".

back to "scontrol show config").

purge the request and job if/when the node changes to state DOWN.

re-issuing it (reduces communications overhead).

KILL_JOB RPC to the slurmd, repeatedly if needed, but don't confirm it).
(gnats:326)

sent in a more timely fashion.

using node hostlist format.

for node registration, which is relatively rare).

very quickly due to a race condition (purge shared memory before completely
set up).

getting the configuration form slurmctld (which could be down).

primary and secondary controllers.

between primary and backup. The request has a brief window in which it can
abort and we want to decrease the likelyhood of that happening by retrying
less frequently when we know control is transistioning.

is still waiting to take control (rather than one long wait).

Slurmctld must be restarted for changes in these configuration parameters
to take effect. Previously these values would change, but there would be
no change in the already loaded plugin.

(jobcomp/none) in the configuration data structure.