Support example html in comments and add API to access to Section

I forked kss from @mkdynamic and merged with the latest master from the https://github.com/kneath/kss repo.  This PR contains the updates that there were part of https://github.com/kneath/kss/pull/56 that allowed for putting example html in the comments as follows:

```
// A basic button.
//
// :hover    - The hover state
// :active   - The pressed state
// :disabled - The disabled state
//
// <button class="m-btn $modifier-class">Button</button>
//
// Styleguide 1.1
```