Remove #include "config.h" from files that have no #ifdef blocks.

Found semi-automatically with:
for a in $( for i in $(grep -r \"config.h\"|cut -f 1 -d : ) ; \
do echo -n "$i "; grep '#if' $i | wc -l  ; done \
|grep \ 0 |cut -f 1 -d ' ' ) ; do vim $a ; done