Notifications

Notifications were broken on the latest Chrome. Chrome deprecated the old `wekitNotifications` API, and now uses the new [Web Notifications API](https://developer.mozilla.org/en-US/docs/Web/API/Notification/Using_Web_Notifications).

I had to update Modernizr for it to accurately detect the new notification capabilities in browsers (used the same custom build as before). Then I updated the notifications plugin to use the new API for requesting and checking permissions, and creating the notifications.

These new notifications now work in [Chrome, Firefox, Safari, and Opera](http://caniuse.com/#feat=notifications).