Fix issue where jobs still pending after a reservation would remain
in waiting reason ReqNodeNotAvail.
Update last_job_update when a job's state_reason was modified.

Some of these were resulting in the state of a job not being updated
correctly to tools like sview.
Minor debugging change, and cleaner initialization.
Free job_ptr->state_desc where ever state_reason is set.
Fixed sacct.1 and srun.1 manual pages which contains a hyphen where
    a minus sign for options was intended.
Move the comment from 2.6.7 to 2.6.8
sinfo - Make sure if partition name is long and the default the last char
doesn't get chopped off.
task/affinity - Protect against zero divide when simulating more hardware
than you really have.
Merge remote-tracking branch 'origin/slurm-2.6'

Conflicts:
	src/slurmctld/job_scheduler.c