Removed Simple Notification Type

The simple notification type is not in the APIs and I get an error
stating that only basic, image, and list are valid types. Using Chrome
29.
Remove onDisplayed Event

The onDisplayed event is not in the APIs and an error occurs using
Chrome 29.
Removed notificationDisplayed...

...as it was no longer used when I removed files from a previous commit.
Merge pull request #120 from jamierytlewski/master

Removing features that are not in the docs or working