code: public <A extends Annotation> CRestBuilder bindAnnotationHandler(Class<? extends AnnotationHandler<A>> handler, Class<A> annotationCls){
          return bindAnnotationHandler(handler, annotationCls, Collections.<String, Object>emptyMap());
      }
docs: <p>Binds an annotation handler for the given annotation.</p>
  <p>Can be used to tell <b>CRest</b> how to handle user-defined annotation used in interfaces.</p>
  @param handler The user-defined annotation handler
  @param annotationCls The user-defined annotation
  @param <A> Used-defined annotation type
  @return current builder