Add Gnulib module "idpriv-droptemp"
Gnulib module "idpriv-droptemp" finishing touches
lib/parse_ini.c - Initial drop privs

Handling the race condition left from suid bins. Moving previous patches from my private copy.
lib/parse_ini.c - Cleaner and more flexible - suid

Adapted from M-P 91d04ad6 and 48025ff3 around the existing changes.