Major refactor and conversion to Bootstrap 3

New:
* Bootstrap 3 layout
* Built-in header and footer generators (opt-out configurable)
* Ship MediaWiki Sanitizer.php

Changes (some of them anyway):
* Refactor mock for mediawiki classes

Removed methods:
* doHtmlHead
* doStartBodyWrapper

Removed misc:
* jQuery UI (unused)
* Non-js-minified constants (unused)
  - KR_MINIFY_ON
  - KR_MINIFY_OFF