Refine destination semantics for msg-handling methods

After this change, annotated message handling methods configured to use
a destination prefix (e.g. "/app") no longer have to include the prefix
in their mapping. For example if a client sends a message to "/app/foo"
the annotated methods should be mapped with @MessageMapping("/foo").

spring-messaging/src/test/resources/log4j.xml

@@ -12,7 +12,7 @@
 	</appender>
 
 	<logger name="org.springframework.messaging">
-		<level value="info" />
+		<level value="trace" />
 	</logger>
 
 	<logger name="org.apache.activemq">