Getting the title based on the attribute model

[unclead]

Great solution, but the 'title' question isn't solved.
The '+' sign staying there alone, without title, I can't find the proper solution unless the one below.
Probably we need a new property to turn on/off the title and for BC.
(I think we need a title when 'allowEmptyList' is true...)

    protected function guessColumns()
    {
        if (empty($this->columns) && $this->hasModel()) {
            $this->columns = [
                [
                    'name' => $this->attribute,
                    'type' => MultipleInputColumn::TYPE_TEXT_INPUT,
                    'title' =>$this->model->getAttributeLabel($this->attribute), // recommended line
                ]
            ];
        }
    }

[unclead]

closed via b483b48