Fix for Bug40263. Make the wiki prettier.

These commits make extensive changes to the reviki templates and rendering.

* Makes use of bootstrap CSS/JS grid for responsive layout.
* Templates/markup now renders to HTML5 instead of XHTML (necessary because of the use of bootstrap) so some markup rules have changed (e.g for self closing tags ````<br/> -> <br>````).
* The layout of the Attachments page is improved as requested in https://bugs.corefiling.com/show_bug.cgi?id=43907.
* Upgrade JS jquery to 1.11.0 and jquery UI to 1.10.4.

The use of bootstrap (e.g data attributes on tags) means that reviki renders to HTML5 instead of XHTML, so rendered page validation is now performed using jsoup (http://jsoup.org/) instead of xhtmlvalidate.