MB-9765: html escape

Change-Id: I9dae706ee275aa068f58415d474560f2056d5d8a
Reviewed-on: http://review.couchbase.org/31247
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>