Implement equals() with compareTo().

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5379 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/crowd/chat/data/ChatChannel.as

@@ -42,7 +42,7 @@ public /*abstract*/ class ChatChannel extends SimpleStreamableObject
     // from interface Equalable
     public function equals (other :Object) :Boolean
     {
-        throw new Error("abstract");
+        return compareTo(other) == 0;
     }
 
     // from interface DSet_Entry