Logging: make SLF4J record to JCL

Tomcat uses Java Commons Logging. With this change, SLF4J (used by our application) should hook into that.

This intends to make the logs generated by our app visible in Tomcat's logs.

pom.xml

@@ -229,9 +229,15 @@
         </dependency>
         <dependency>
             <groupId>org.slf4j</groupId>
-            <artifactId>jcl-over-slf4j</artifactId>
+            <artifactId>slf4j-jcl</artifactId>
             <version>${slf4j.version}</version>
         </dependency>
+        <dependency>
+            <groupId>commons-logging</groupId>
+            <artifactId>commons-logging</artifactId>
+            <version>1.3.0</version>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>org.json</groupId>
             <artifactId>json</artifactId>