Adicionar setas para cima/baixo ao acordeão Bootstrap

$(function () {

    var active = true;

    $('#collapse-init').click(function () {
        if (active) {
            active = false;
            $('.panel-collapse').collapse('show');
            $('.panel-title').attr('data-toggle', '');
            $(this).text('Enable accordion behavior');
        } else {
            active = true;
            $('.panel-collapse').collapse('hide');
            $('.panel-title').attr('data-toggle', 'collapse');
            $(this).text('Disable accordion behavior');
        }
    });
    
    $('#accordion').on('show.bs.collapse', function () {
        if (active) $('#accordion .in').collapse('hide');
    });

});

.panel-title:hover {
     cursor: pointer;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.2/jquery.min.js"></script>
<link href="https://netdna.bootstrapcdn.com/font-awesome/3.2.1/css/font-awesome.min.css" rel="stylesheet"/>
<script src="https://netdna.bootstrapcdn.com/bootstrap/3.0.0/js/bootstrap.min.js"></script>
<link href="https://netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css" rel="stylesheet"/>
<button id="collapse-init" class="btn btn-primary">
    Disable accordion behavior
</button>
<br/><br/>

<div class="panel-group" id="accordion">
    <!-- First Panel -->
    <div class="panel panel-default">
        <div class="panel-heading">
             <h4 class="panel-title"
                 data-toggle="collapse" 
                 data-target="#collapseOne">
                 Collapsible Group Item #1
             </h4>
        </div>
        <div id="collapseOne" class="panel-collapse collapse">
            <div class="panel-body">
                Anim pariatur cliche reprehenderit, 
                enim eiusmod high life accusamus terry richardson ad squid.
            </div>
        </div>
    </div>
    
    <!-- Second Panel -->
    <div class="panel panel-default">
        <div class="panel-heading">
             <h4 class="panel-title" 
                 data-toggle="collapse" 
                 data-target="#collapseTwo">
                 Collapsible Group Item #2
             </h4>
        </div>
        <div id="collapseTwo" class="panel-collapse collapse">
            <div class="panel-body">
                Anim pariatur cliche reprehenderit, 
                enim eiusmod high life accusamus terry richardson ad squid.
            </div>
        </div>
    </div>
    
    <!-- Third Panel -->
    <div class="panel panel-default">
        <div class="panel-heading">
             <h4 class="panel-title"
                 data-toggle="collapse"
                 data-target="#collapseThree">
                 Collapsible Group Item #3
             </h4>
        </div>
        <div id="collapseThree" class="panel-collapse collapse">
            <div class="panel-body">
                Anim pariatur cliche reprehenderit, 
                enim eiusmod high life accusamus terry richardson ad squid.
            </div>
        </div>
    </div>
</div>
    
    
    
    
    
    
<!-- Post Info -->
<div style='position:fixed;bottom:0;left:0;    
            background:lightgray;width:100%;'>For this SO Question: <a href='http://stackoverflow.com/q/20347553/1366033'>Keep Accordions Open</a>

    <br/>Find documentation: <a href='http://getbootstrap.com/javascript/#collapse-usage'>Bootstrap Collapse Usage</a>

    <br/>Fork This Skeleton Here <a href='http://jsfiddle.net/KyleMit/kcpma/'>Bootrsap 3.0 Skeleton</a>

    <br/>
    <div>