Updated mediawiki/extensions
Project: mediawiki/extensions/BetaFeatures  41abde44878d67e8333a670504d40b3a55e56c85

Keep pretty checkboxes accessible

Use the clip technique for hiding them.

http://adaptivethemes.com/using-css-clip-as-an-accessible-method-of-hiding-content

Change-Id: If3327148381ff18a34d6aef530e96bdbb6d101d3