SyncRepl aka LDAP Content Synchronization Operation

• The protocol is specified by RFC 4533.
• OpenLDAP API for SyncRepl is described in manual page ldap_sync.
  • OpenLDAP configuration for testing is described in Zytax LDAP book chapter 7.
• Support to 389 DS was added in their tickets #47388, #47803, #47805
  • Configuration for 389 DS can be found in FreeIPA commit 689382dc833e687d30349b10a8fd7dc740d54d08.