Support GitHub's starred event

Against our better instincts, GitHub send 'star' event as 'watch'.
This is for compatibility with old API...

For example:
![2014-10-02 0 02 31](https://cloud.githubusercontent.com/assets/290782/4477319/1625e280-497d-11e4-802d-e62875161fa9.png)

What is "as pending"?