Enforce JobRequeue configuration parameter

Previously a node failure would always requeue the job
acct_gather_energy/ipmi - Add delay before retry on read error.

If slurmd fails to get IPMI value, then I propose to force to wait 1 second instead of asking BMC again. (Part 3/4 of the patch).
If IPMI init fails when slurmd forces to update the value, then we should not update the value. (Part 4/4 of the patch
Part 1/4 and 2/4 add a security in IPMI init because the function can be call several time.
This force to return SLURM_FAILURE if the first call failed, since the other call will not do anything.

bug 469
Document latest patch changes in NEWS
Add contributor to our web page
Problem allocating threads with GPUs

If a node has GRES and multiple threads per core the select/cons_res
plugin can get stuck in an infinite loop.
See bug 475
Contributed by:
PREVOST Ludovic
NEC HPC Europe
Merge branch 'slurm-2.6' of http://github.com/SchedMD/slurm into slurm-2.6

Conflicts:
	NEWS
Correction to previous commit

I did the merge improperly
Update TotalView configuration file in FAQ
proctrack/cgroup - Fix for race condition

Add cgroup create retry logic in case one step is starting at the
same time as another step is ending and the logic to create
and delete cgroups overlaps.
bug 447
Improve description of a function
Improve setting of job wait "Reason" field.

Without this change a job with a reason of WAIT_PART_DOWN,
WAIT_PART_INACTIVE, WAIT_PART_NODE_LIMIT, WAIT_PART_TIME_LIMIT, or
WAIT_QOS_THRES would not be cleared when that reason no longer
applied.
Add info about MySQL configuration

Specifically setting innodb_buffer_pool_size=64
in my.conf
Merge branch 'slurm-2.6'

Conflicts:
	NEWS
	src/plugins/proctrack/cgroup/proctrack_cgroup.c