Fix bug #66283 (Segmentation fault after memory_limit)

There are situations where mysqlnd dupliates zvals while freeing result
sets. If the memory_limit is reached during this operation the engine
will bailout. This patch makes sure that a later attempt (during
RSHIUTDOWN) won't cause a double free, instead we rely on the engine to
free emalloc()ed memory after bailout.
fix NEWS formatting
fixed post deactivate signature in ext\libxml
fix news
5.4.26 next
fix CVE ref for bug #66060
Re-fixed bug #66469
Fixed previous commit may delete unwanted cookies. Sync tests from upper branches.
fixed missing usleep() prototype in pgsql
fix zts
fixed test