Cosmetic change
select/cons_res, enforce ntasks-per-socket for core allocations

Select/cons_res - If the job request specified --ntasks-per-socket and the
allocation using is cores, then pack the tasks onto the sockets up to the
specified value. Previously it would ignore the ntasks-per-socket
parameter and distribute tasks across sockets
BGQ - handle instances where jobs aren't freed when cnodes go into
SoftwareFailure state.
BGQ - If a cnode goes into an 'error' state and the block containing the
cnode does not have a job running on it do not resume the block.
BGQ - Only remove blocks on an initial poll of the system and when
they are missing and on a sub midplane system.
Update accounting docs to talk about adding the database before you start
the DBD.

Signed-off-by: Danny Auble <da@schedmd.com>
BGQ - Handle blocks that don't free themselves in a reasonable time better.
BGQ - Fix for signaling steps when allocation ends before step.
Fix for backfill scheduling logic with job preemption

Without this fix, jobs that should be initiated by the backfill
scheduler based upon the preemption of other jobs will not be
started.
Merge branch 'slurm-2.5'