Add missing config.h include where appropriate.

Automatically found by looking for files relying on macro definitions from
config.h.

Ugly one-liners used to automate this are:

tim@zoidberg:~/slurm$ for def in $(grep undef config.h.in |cut -f 2 -d ' ' );
do for f in $(grep -r $def src/ |cut -f 1 -d : | sort -u);
do if [ $(grep -q "#include \"config.h\"" $f; echo $? ) -ne 0 ];
then echo $def $f ; fi ; done ; done  > missing-includes
tim@zoidberg:~/slurm$ for aaa in $(grep -v \.in missing-includes |
grep -v \.am |grep SLURM_VERSION|grep -v malloc |cut -f 2 -d ' '|sort -u );
do vim $aaa ; done
tim@zoidberg:~/slurm$ for aaa in $(grep -v \.in missing-includes |
grep -v \.am |grep -v VERSION|grep -v malloc |cut -f 2 -d ' '|sort -u );
do vim $aaa ; done