Adds WP-Cli support. Fixes #689

WP-Cli is the command line interface for WordPress. About 40% of the websites are Powered by WordPress, so this tool is mostly used by many WordPress Developers including me.

![image 1](https://cloud.githubusercontent.com/assets/3774827/3900169/2d368ef6-2287-11e4-9135-ab0b5a200f74.png)