Update combodate.js

[ali33]

I written some lines for firstItem at fillCommon

<input type="text" class="hour-time" id="time_min" data-format="HH:mm" data-template="HH : mm" name="datetime">
<script>
                   $(function () {
                        $('.hour-time').combodate({
                            firstItem: {h:'Select hour',m:'Select minute'},
                            minuteStep: 1
                        });
                    });
</script>