the solution of TESB-10959 for sam-agent

1) make "EventFeature" a interface
2) create a new class named "EventFeatureImpl" which "extends AbstractFeature implements EventFeature"

Nothing need to be changed for existing CXF services/clients with sam enabled.
&lt;osgi:reference id="eventFeature" interface="org.talend.esb.sam.agent.feature.EventFeature" /&gt;
or:
&lt;jaxws:features&gt;
    &lt;ref bean="eventFeature"/&gt;
&lt;/jaxws:features&gt;