patch set for kcc intra-site topology

[Dave Craft]

Asking for a review / comments on:

https://github.com/wimberosa/samba/tree/kcc-stable

This is a set of nine separate patches against the
tree as of yesterday.   They build incrementally from the
initial missing flags in libds/common/flags.h up to the last
commit which introduces the kcc_intra_topology.c file.   Obviously
latter patches are dependent on earlier patches.

Note also that the kccsrv_simple_topology() is still the
default implementation and the newer intra-site topology
code is only entered if you set the parametric option
     kccsrv:intrasite = true
in smb.conf.    This simple topology is meant to remain
the default until we have surety that the newer implementation
is nigh perfect (which it currently is not)

The intra-site topology implementation is mimic'ing the
MS-ADTS section 7.2.2.2 Intrasite Connection Creation.

Some things are still missing and I'm working them currently.
Most notably this does not produce every graph ring described
in that document since I need to rerun the algorithm again
with NTDSSETTINGS_OPT_IS_TOPL_DETECT_STALE_DISABLED
set as well as running an additional loop if it is the GC (latter part
of algorithm description in 7.2.2.2).

This also does not properly introduce kCCFailedLinks or
kCCFailedConnections as those seem to be runtime attributes
that are going to have to be tracked during replication communication
(as opposed to database attributes)

Lastly I have to figure out how to introduce good tests and there
are still some multi-site and application naming contexts that I need
to compare against a windows server implementation.

Comments appreciated
-- 
Regards, Dave Craft
Cut the headlights and put it in neutral.