Adds new method for rule merge

IMPORTANT: SecDefaultAction specified on a child configuration will
overwrite the ones specified on the parent; Previously it was
concatenating.

src/actions/disruptive/pass.cc

@@ -30,7 +30,7 @@ namespace disruptive {
 
 
 bool Pass::evaluate(RuleWithActions *rule, Transaction *transaction,
-    std::shared_ptr<RuleMessage> rm) {
+    RuleMessage &rm) {
     intervention::free(&transaction->m_it);
     intervention::reset(&transaction->m_it);