Added method #hasChangedHistory. JM-40

git-svn-id: http://svn.igniterealtime.org/svn/repos/messenger/trunk@560 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/messenger/muc/HistoryStrategy.java

@@ -249,4 +249,15 @@ public class HistoryStrategy {
             }
         }
     }
+
+    /**
+     * Returns true if there is a message within the history of the room that has changed the
+     * room's subject.
+     *
+     * @return true if there is a message within the history of the room that has changed the
+     *         room's subject.
+     */
+    public boolean hasChangedSubject() {
+        return roomSubject != null;
+    }
 }