+5638. [bug] Improvements related to network manager/task manager
+ integration:
+ - added isc_managers_create() and _destroy() functions
+ to handle setup and teardown of netmgr, taskmgr,
+ timermgr and socketmgr since these require a
+ precise order of operations now.
+ - event queue processing is now quantized to prevent
+ infinite looping.
+ - the netmgr can now be paused from within a netmgr
+ thread.
+ - fixed deadlocks due to conflict between netmgr
+ pause/resume and listen/stoplistening operations.
+ [GL #2654]
+
5637. [placeholder]
5636. [bug] Check that zone files for 'dnssec-policy' zones are