WaniKani Notifier v2 per martinlj

Ported from the Chrome extension by BleckJeck

Simple Notifier and Launcher for WaniKani Reviews and Lessons. Works with API v2

Notifies you when your reviews are due. There's not much else to it.
Made mostly for fun, works with the WaniKani API v2.

Features:
- A badge shows how many reviews are due (you can tick a box in the settings page to get politely reminded of your lessons as well).
- Click on the extension to open a pop-up with links to your lessons and reviews.