Add a tag
@param  {HTMLElement} item
function(item) {
  var that = this,
      r;

  var docFrag = document.createDocumentFragment();
  var option = this.options[item.idx];
  var data = this.data ? this.data[item.idx] : option;
  var content = this.customSelected ? this.config.renderSelection(data) : option.textContent;

  var tag = util.createElement("li", {
    class: "selectr-tag",
    html: content
  });
  var btn = util.createElement("button", {
    class: "selectr-tag-remove",
    type: "button"
  });

  tag.appendChild(btn);

  // Set property to check against later
  tag.idx = item.idx;
  tag.tag = option.value;

  this.tags.push(tag);

  if (this.config.sortSelected) {

    var tags = this.tags.slice();

    // Deal with values that contain numbers
    r = function(val, arr) {
      val.replace(/(\d+)|(\D+)/g, function(that, $1, $2) {
        arr.push([$1 || Infinity, $2 || ""]);
      });
    };

    tags.sort(function(a, b) {
      var x = [],
          y = [],
          ac, bc;
      if (that.config.sortSelected === true) {
        ac = a.tag;
        bc = b.tag;
      } else if (that.config.sortSelected === 'text') {
        ac = a.textContent;
        bc = b.textContent;
      }

      r(ac, x);
      r(bc, y);

      while (x.length && y.length) {
        var ax = x.shift();
        var by = y.shift();
        var nn = (ax[0] - by[0]) || ax[1].localeCompare(by[1]);
        if (nn) return nn;
      }

      return x.length - y.length;
    });

    util.each(tags, function(i, tg) {
      docFrag.appendChild(tg);
    });

    this.label.innerHTML = "";

  } else {
    docFrag.appendChild(tag);
  }

  if (this.config.taggable) {
    this.label.insertBefore(docFrag, this.input.parentNode);
  } else {
    this.label.appendChild(docFrag);
  }
}