Fix type attributes not required in html5. Thanks @nternetinspired

Issue reported by @nternetinspired in the template9 branch:
https://github.com/Joomla3-Admin-template/joomla-cms/issues/114

To enable the html5 mode in the template use:

    JFactory::getDocument()->setHtml5(true);

The type attributes will dissappear.

Issue tracker:
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=32162&start=0