A jquery animation controller, offer a few awesome methods to controll your animation elems,methods include "pause", "fastForward", "rewind" etc. see demo.html to find how to use this plugin.
jquery 动画控制插件，为正在动画的元素 提供了 暂停，快进，快退方法，详细用法见demo。
TODO: 更强大的自定义速率（目前默认10%）