MediaWiki theme: Fix button layout in ButtonGroup-/SelectWidgets in IE 9
MediaWiki theme: Fix button layout in ButtonGroup-/SelectWidgets in IE 9

Applying `min-width` only on icon-only, framed ButtonWidgets.

Bug: T158728
Change-Id: I53f24a82dafa9287722dc5988877f829f4378c48

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui