Added the "Overall" page

   While not keeping track of the wasted time for more than 30 days, we
   are keeping a all-time total of the time wasted. The user should have
   access to this information.

   We are taking the total form each blacklisted website and pass the
   data to google charts to be representad as a nice bar graph.

   We have a third page which contains a bar-chart with each website
   represented as a bar.
   Also in this commit we added a nice icon for the extension.
   Changed the name of the link to options page from "options" to
   "settings"
   Added a save-confirmation message when saving the changes in options.