[ale] Construct the header in smaller chunks.
[ale] Construct the header in smaller chunks.

Change-Id: Ia795ea8a0d7cd10732e5d03225e175207f513c3d
Reviewed-on: http://review.couchbase.org/50872
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Tested-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

ceejatec/ns_server,mschoch/ns_server,ceejatec/ns_server,ceejatec/ns_server,mschoch/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,ceejatec/ns_server,membase/ns_server,membase/ns_server,nimishzynga/ns_server,mschoch/ns_server,mschoch/ns_server,ceejatec/ns_server,membase/ns_server,nimishzynga/ns_server,membase/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,membase/ns_server,membase/ns_server,mschoch/ns_server,mschoch/ns_server,ceejatec/ns_server