sssvlv overlay

the "(entrycsn>=cookie)" part that was inserted) when checking whether a
change needs to be replicated, otherwise we lose DELETES that happen during
the refresh phase (ITS#6555).

when deleting the syncprov overlay from a database (when compiled with
-DSLAP_CONFIG_DELETE)

LDAP_SYNC_NEW_COOKIE intermediate results. (ITS#6459)

to the backend any more

all responses are now serialized.

first matchops call

back-config operation (and could wipe out the state otherwise)

don't checkpoint when adding the context entry to a DB