function dequeue(element, queueName, skip) {
    if (queueName !== false) {
        if (!isString(queueName)) {
            queueName = "";
        }
        var data = Data(element),
            animation = data.queueList[queueName];
        if (animation) {
            data.queueList[queueName] = animation._next || null;
            if (!skip) {
                animate(animation);
            }
        } else if (animation === null) {
            delete data.queueList[queueName];
        }
        return animation;
    }
}
Start the next animation on this element's queue (named or default).

@returns the next animation that is starting.