<li><strong>label</strong> – The label on the button. Default is the filename.</li>
<li><strong>icon</strong> – Optional icon name. Must be from <a class="reference external" href="http://fontawesome.io/icons/">http://fontawesome.io/icons/</a></li>
<li><strong>tooltip</strong> – An optional tooltip.</li>
<li><strong>style</strong> – Default is ‘’. Supported values are “success”, “info”, “warning”, and “danger”.</li>
<li><strong>cb</strong> – Optional callback function.</li>
</u