Restyle using Munaf Assaf's CSS and add GuidedTour steps/tour.

* Remove bucketting.
* Add readme with instructions, dependency, and license (GPLv2+).
* Add jshint.
* Move remaining hook into GettingStarted.hooks.php.
* Move arrow into i18n message.

Change-Id: Ib13103adc2190b8ae5a39203af79f1ee87af4228