Ticket 47577 - crash when removing entries from cache

Bug Description:  when the dn of an entry in the cache was adjusted to the parent dn, for soenm time
	teh dn was not defined, anothe thread accessing the dn of teh chached entry could crash

Fix Description:   hold the cache mutex when modifyingthe dn of an entry in the cache

https://fedorahosted.org/389/ticket/47577

Reviewed by: rmeggins
(cherry picked from commit 7272dbda7f43974eed003cbcfc0ddd57fe433687)
Ticket #47581 - Winsync plugin segfault during incremental backoff

Bug description: Once WinSync backoff timer is set, even if the
protocol that the backoff timer belongs to is deleted by removing
the windows sync agreement, the timer is not deleted from the event
queue.  Thus the timer is expired and backoff is called, it crashes
the server since the protocol handle is already freed, then.

Fix description: Make sure to delete the backoff timer when
1) a windows sync agreement is removed and the protocol is deleted, and
2) a new backoff timer set and there is already a backoff timer set up.

https://fedorahosted.org/389/ticket/47581

Reviewed by rmeggins (Thank you, Rich!!)
(cherry picked from commit d70e66b2157ce3ba40c5e1cb074c2d5c150ddc5b)
Ticket #47581 - Winsync plugin segfault during incremental backoff (phase 2)

Fix description: Apply the previous patch Ticket #47581 against the
replication plug-in (repl5_inc_protocol.c):
Make sure to delete the backoff timer when
1) a replication agreement is removed and the protocol is deleted, and
2) a new backoff timer set and there is already a backoff timer set up.

https://fedorahosted.org/389/ticket/47581

Reviewed by rmeggins (Thank you, Rich!!)
(cherry picked from commit 8eecc43e0160e132949ed504162b4536d6040620)
Ticket 47588 - Compiler warnings building on F19

This addresses a few compiler warnings that show up when building
on F19.  The issues are minor (unused typedef and an incorrect
usage of memset in some debugging ifdef'd code).
(cherry picked from commit cafc4eb7a16e5ee4b90922fa0000e86d35290030)