Save and restore batch script's argc & argv across slurmctld restarts.

Convert all accessors to use exclusively pointers; this should fix many of the 64-bit incompatibility problems

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.