Added slf4j-log4j compatibility jar

dddsample/pom.xml

@@ -253,6 +253,11 @@
       <version>1.5.6</version>
     </dependency>
     <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>jcl-over-slf4j</artifactId>
+      <version>1.5.6</version>
+    </dependency>
+    <dependency>
       <groupId>javassist</groupId>
       <artifactId>javassist</artifactId>
       <version>3.8.0.GA</version>