Moved UserIdentifier to data.

We'll be using it on the client as well, because I'm going to have
to finally pay down some code debt (and do something actually
useful for the creators): expose memberIds to the whirled screen-game api.


git-svn-id: svn+ssh://src.earth.threerings.net/vilya/trunk@815 c613c5cb-e716-0410-b11b-feb51c14d237

src/as/com/threerings/parlor/game/data/UserIdentifier.as

@@ -0,0 +1,15 @@
+//
+// $Id$
+
+package com.threerings.parlor.game.data {
+
+import com.threerings.crowd.data.BodyObject;
+
+public interface UserIdentifier
+{
+    /**
+     * Returns the id of the specified user, or 0 if they're not valid.
+     */
+    function getUserId (bodyObj :BodyObject) :int;
+}
+}