don't use deque here; too big for Actor

(not a performance issue; we don't queue up tons of messages.  only use
deque when you really need constant time access to the beginning, eg.
for large objects, since deque has both memory overhead and is much
slower than vector for access to the end of the list, since it can't reserve like
vector can)

stepmania/src/MessageManager.h

@@ -20,7 +20,7 @@ private:
 		float fDelayRemaining;
 	};
 	void HandleMessageInternal( const CString& sMessage );
-	deque<QueuedMessage> m_aMessages;
+	vector<QueuedMessage> m_aMessages;
 
 	friend class MessageManager;
 };