Selectize not playing nicely with components it overlaps e.g. CKEditor #1481

// This function is called on the input / select element that was enhanced with selectize.
var fixMouseDownHandling = function() {
  if (!this.selectize) {
    return;
  }

  // Turn off mouse down listener and rely only on click event.
  this.selectize.$dropdown.off('mousedown', '[data-selectable]');

  // Overwrite the mousedown listener used to close the dropdown when the user clicks outside because the code that
  // check if the event target is outside is not right (doesn't take into account that the suggestion display can have
  // multiple nested elements)
  $(document).off('mousedown' + this.selectize.eventNS);
  var self = this.selectize;
  $(document).on('mousedown' + this.selectize.eventNS, function(e) {
    if (self.isFocused) {
      // prevent events on the dropdown scrollbar from causing the control to blur
      if (self.$dropdown.has(e.target).length) {
        return false;
      }
      // blur on click outside
      if (!self.$control.has(e.target).length && e.target !== self.$control[0]) {
        self.blur(e.target);
      }
    }
  });
};