WIP: Ratchet 2.0

The initial launch of Ratchet aimed to provide the simplest way to prototype iPhone apps in HTML, CSS, and JavaScript. It's been pretty quiet around here ever since that initial release but this pull request should give some insight into the upcoming 2.0 release. 

This pull request **doesn't reflect** the final feature set or todo list for version 2.0. We'll be updating the pr with new features and todos as we continue development. Think of this as a living document.

## General

- [x] Redesign components to match the new iOS 7 aesthetic.
- [x] Docs built on Jekyll.
- [ ] Use pygments in Jekyll instead of prettify.js. 
- [x] Switch from a Makefile to using Grunt.
- [ ] Updated design for the docs.

## CSS

With 2.0, Ratchet is going to be rewritten in **SASS**. Among other things, this will allow for greater flexibility in theming the look a feel of your prototypes. We'll also be pruning the CSS to remove unneeded code.

- [x] SASS rewrite
- [ ] Rename component classes to better reflect the HIG.
- [x] Remove the old reset css and use normalize.css instead.
- [x] Remove excess gradients and shadows for iOS 7.
- [x] Remove docs folder
- [ ] General clean up.

### Nav bars

- [x] Now uses the class `.bar-nav` to reflect the HIG.
- [x] Nav bars are now transparent to allow the apps content to bleed through.  
- [x] `.content` now uses padding-top and padding-bottom to allow content to bleed through the nav bar.
- [x] Directional buttons in the `.bar-nav` now use the iOS 7 style arrows.
- [ ] Use Ratchicons for the chevrons

### Tab bars

- [x] Tab bars are now transparent to allow the apps content to bleed through.
- [x] Use Rachticons for tabs.

### Lists
- [x] Rename to `.table-view` to better reflect the HIG.
- [ ] Include active states to list items when `:active`.
- [ ] Support for left aligned Ratchicons.
- [ ] Support for images in lists.

### Buttons

- [x] Additional styles for outlined and filled buttons.
- [ ] Buttons can now include Ratchicons.
- [x] Support for `button` element.

### Counts

- [x] Support for normal and filled counts

### Popovers

- [x] Popovers now use normal `.bar-nav`
- [x] Backdrop element now has a dark overlay added to offset the popover element.

### Push

- [x] Update push animations based on iOS 7.

## Ratchicons

With 2.0 we'll be introducing Ratchicons, custom designed icons for Ratchet. We'll be adding a base set and continuing to expand as we go.

- [ ] Include base set of Ratchicons.

## Themes

- [x] Default iOS 7 theme.
- [x] Classic Ratchet theme based on the v1 colors.