make sched_timeout logic the same as that in backfill to avoid message timeouts
in slurmctld_background(), tweak times to spread out the work a bit more

    if required locks are not immediately available. This will improve
    performance when heavy-weight functions such as backfill scheduler are
    running.

Pulled Cray logic out of common/node_select.c into it's own select/cray plugin cons_res is the default.  To use linear add 'Linear' to SelectTypeParameters.
-This line, and those below, will be ignored--

M    configure
M    src/plugins/select/Makefile.in
M    src/plugins/select/Makefile.am
M    src/plugins/select/linear/select_linear.c
M    src/plugins/select/cons_res/select_cons_res.c
A    src/plugins/select/cray
A    src/plugins/select/cray/other_select.c
A    src/plugins/select/cray/Makefile.in
A    src/plugins/select/cray/other_select.h
A    src/plugins/select/cray/Makefile.am
A    src/plugins/select/cray/select_cray.c
M    src/common/slurm_selecttype_info.c
M    src/common/node_select.c
M    slurm/slurm.h.in
M    configure.ac
M    NEWS

    if POLLHUP flag was set at the same time).

zero and 1 CPU on node one instead of 2 and 2)

    DOWN nodes.

    required hostlist.

    oversubscribe resources.

same second as node boots).

    names specified are invalid, avoid invalid memory reference.