be able to find the LDAP NSS module, which is normally installed in
Glibc's prefix (under /lib/libnss_ldap...). Of course, we can't do
that; it wouldn't be pure. As a workaround, we simply add nss_ldap
to the LD_LIBRARY_PATH of the nscd daemon, which every other program
uses for lookups. So we don't have to put nss_ldap in the
LD_LIBRARY_PATH of every program.
svn path=/nixos/trunk/; revision=7684
