Add CollapseNav

* This adds collapse nav since it was removed in the core of mediawiki.
* This also fixes another issues with javascript. the problem was when you
clicked the tabs at the top javascript would break. it should be fixed
now.
* Also deletes some unused images and icons and adds more svg version of images.
Note this will only work with mediawiki 1.24 or higher.

Change-Id: I9c0bbf254feb15c0f0b7ddc98c404dd465859fc4