Docstring and Sphinx support

closes #3 

This adds a ton of documentation, as well as support for Sphinx, which compiles documentation to an HTML website.

![screen shot 2014-10-10 at 1 56 49 pm](https://cloud.githubusercontent.com/assets/2433509/4596762/d5e8f1ae-50a6-11e4-9ef5-64fa7fe367f8.png)

This can be simplified a lot. All of the `|` aren't really necessary since you're doing character sets within them.

`\w == [a-zA-Z0-9_]`
(docs: https://docs.python.org/2/library/re.html)

```python
Regexp(r"([\w-@\|\(\))*")
```