(ITS#6020) MMR sends too many redundant messages

[hyc@OpenLDAP.org]

Full_Name: Howard Chu
Version: HEAD/RE24
OS: Linux
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (76.91.220.157)
Submitted by: hyc


Currently syncprov knows not to send a change back to the originating server,
but it will still send changes back to the server that delivered it. (E.g.,
server 1 replicates to server 2, server 2 to server 3. Server 3 will immediately
try to send the same message back to server 2.)

Syncrepl isn't providing any information for syncprov to know where a change
came from. The fix is for syncrepl to attach the incoming sync_cookie state to
the operation it uses when writing to its own database. Coming in HEAD shortly.