Editor Toolbar Buttons not getting styled

Hi!
The editor toolbar buttons are not getting styled any more in WP 3.9.1 with v 1.6.0.

In my opinion the buttons input.ed_button cm_ed_button need the extra classes button & button-small to inherit the styles from editor.min.css

At WP 3.8.3 with v 1.4.8 the buttons are styled correctly.

See a screenshot of the current state on my installation here

https://ww.wp.xz.cn/plugins/html-editor-syntax-highlighter/