MEDIUM: http-ana: Eval HTTP rules defined in defaults sections

MEDIUM: http-ana: Eval HTTP rules defined in defaults sections

As for TCP rules, HTTP rules from defaults section are now evaluated. These
rules are evaluated before those of the proxy. The same default ruleset
cannot be attached to the frontend and the backend. However, at this stage,
we take care to not execute twice the same ruleset. So, in theory, a
frontend and a backend could use the same defaults section. In this case,
the default ruleset is executed before all others and only once.