[PATCH] s4-drs: Store uSNUrgent for Urgent Replication

[tridge at samba.org]

Hi Fernando,

Thanks for the patches! I've pushed them to master.

I've also fixed up the DRS option bit defines, so
DRSUAPI_DRS_SYNC_URGENT should now be correct for the drepl_notify.c
code. 

Will you do a patch to add that bit for urgent notifies? The changes
should be quite simple:

 - add an urgent bool to struct dreplsrv_op_notify_state
 - add a urgentUSN argument to dreplsrv_schedule_notify_sync()
 - fill in the bit on the wire

Then as a separate patch it would be good to add a testsuite for this
if we can.

Cheers, Tridge