yiisoft/yii2 — pull request #5799 by aleksanderd (2014-10-29 11:10:08+00:00)
Title: Allow to use attrs like 'tagName' in ButtonGroup->buttons configs

Pass all the button's config array to Button::widget() instead of creating new one item by item. Now allowed to pass in ButtonGroup button's configs any possible attributes(like tagName, encodeLabel, etc).