Demo, bug fixes, cleaner docs

  * Better demo
  * Cleaner docs
    * Cleaned up README
    * Better layout of OpenBadgesDisplayer.litcoffee
  * Better usage / unbaking
    * Can manually unbake again
    * User no longer needs to create an instance of openbadges-displayer
  * Bug fixes
    * Modal and overlay display and alignment fixes
    * Removed ability to unbake badge multiple times.
  * Refactored a few functions for cleaner code.