Improved backward compatibility with default audit settings

- audit.useNewConfig=false is now the default setting and has a new meaning
- In this mode, audit information is broadcast to BOTH the old and new audit configuration, meaning that e.g. you can enjoy new RM and CMIS auditing capabilities whilst still retaining compatibility with your old audit configuration
- When audit.useNewConfig=true only the new config/alfresco/audit/*.xml configuration will be used exclusively. NOT config/auditConfig.xml.
- Note that auditing is still switched off by default and must be switched on with audit.enabled=true
- You can switch on and off individual applications in the new config using
   - audit.repository.enabled
   - audit.cmischangelog.enabled
   - audit.dod5015.enabled
- Simple!

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@18885 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/audit/model/AuditModelRegistryImpl.java

@@ -152,6 +152,15 @@ public class AuditModelRegistryImpl extends AbstractPropertyBackedBean implement
         start();
     }
     
+    /**
+     * {@inheritDoc}
+     */
+    public boolean isAuditEnabled()
+    {
+        String value = getProperty(PROPERTY_AUDIT_ENABLED);
+        return value != null && value.equalsIgnoreCase("true");
+    }
+
     /**
      * Enables audit and registers an audit model at a given URL. Does not register across the cluster and should only
      * be used for unit test purposes.