Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/MarqueeElement.dartdoc

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// WARNING:
-//   This file contains documentation that is merged into the real source.
-//   Do not make code changes here.
-
-/// @domName HTMLMarqueeElement
-interface MarqueeElement extends Element {
-
-  /** @domName HTMLMarqueeElement.behavior */
-  String behavior;
-
-  /** @domName HTMLMarqueeElement.bgColor */
-  String bgColor;
-
-  /** @domName HTMLMarqueeElement.direction */
-  String direction;
-
-  /** @domName HTMLMarqueeElement.height */
-  String height;
-
-  /** @domName HTMLMarqueeElement.hspace */
-  int hspace;
-
-  /** @domName HTMLMarqueeElement.loop */
-  int loop;
-
-  /** @domName HTMLMarqueeElement.scrollAmount */
-  int scrollAmount;
-
-  /** @domName HTMLMarqueeElement.scrollDelay */
-  int scrollDelay;
-
-  /** @domName HTMLMarqueeElement.trueSpeed */
-  bool trueSpeed;
-
-  /** @domName HTMLMarqueeElement.vspace */
-  int vspace;
-
-  /** @domName HTMLMarqueeElement.width */
-  String width;
-
-  /** @domName HTMLMarqueeElement.start */
-  void start();
-
-  /** @domName HTMLMarqueeElement.stop */
-  void stop();
-}