Fix bug that would leak memory and over-write the AllowGroups field

if on "scontrol reconfig" when AllowNodes is manually changed using
scontrol since last slurmctld restart.
Merge branch 'slurm-2.5'
Replace local hdf5.m4 script with gnu's
HDF5 - Note about why we have to for the deprecated symbols option

Signed-off-by: Danny Auble <da@schedmd.com>
ran autogen.sh
HDF5 - Remove deprecated symbols
Minor edit about deprecated symbols on old systems
HDF5 - more deprecated symbol removal.
Add links to UBMoD accounting tool
I've found several problems in the user guide. Some are cut/paste when replicating data types, some grammatical, or to make it read a little better.
Remove trailing white spaces as per programming guide.
Updated the MPICH2 documentation.
Correct the -m --distribution documentation man pages.
Correct the memory size ot the array which should be NULL terminated.
Avoid side effect instructions and do not increment a counter while
accessing the array element but separate the instructions as per programming guide.
Update the documentation about PMI2 support in MPI.
Convert enum to string
minor debug edit
remove unneeded init and fini
PROFILING - Make sure polling threads end correctly
ACCT_GATHER - handle suspending correctly for polling threads.