HTML5 new types for input element

HTML5 new types for input element

HTML5 introduced new types for the input element. For some reasons we
never added them to Html::openElement which would thus strip them even
in HTML5 mode.

The issue is:
 $wgHtml5 = true;
 Html::element( 'input', array( 'type' => 'color' );
 # -> "<input />"

With this patch, we returns: <input type="color" />

Change-Id: I7de373635d0eb47f788d1d664c3a913c8801efd6