Ticket 47599 - Reduce lock scope in retro changelog plug-in
Description: Use RW locks for protecting the change numbers.
We still need to do the locking in retrocl_po.c as we need to
serialize the actual updates.
https://fedorahosted.org/389/ticket/47599
Reviewed by: richm(Thanks!!)
(cherry picked from commit e2c42bced86bac235ac56ae98eed303f61ebd15e)