MB-10083 Enable memcached SSL support.

Change-Id: I78b8bb69091b520e5c0a26a9256caaf3d5ab2854
Reviewed-on: http://review.couchbase.org/33513
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>