Update res_search check and place behind --enable-dns.

subdirectories; add explicit dependencies for subdirs that need them.

LDAPext discussions).
Add attrs and attrsonly support to monitor/config info.
Add rdn attributes to schema/monitor/config.
Add extensibleObject objectclass to schema/monitor/config.
Add top objectclass to rootdse/monitor/config.
Remove opattrs option from send_search_entry().

as it's not stored the directory.

all cases (including root dse).

Rework sys_errlist detection to set HAVE_SYS_ERRLIST if sys_errlist
exists.  If it declaration is needed, DECL_SYS_ERRLIST is also set.

of explicit acconfig.h entries.

time, skipping the filter, for instance.  Also, we were parsing
twice the scope and the filter.  I think this change is right,
but could use more eyeballs...

an OID or a proper type string (letter followed by 0 or more
alnum/-).

NULL does not meet basic syntax rules.