Js improvements

Fixes #281 and fixes #273

- Adds fastclick
- Move customer js to the bottom of the page
- Move comment hash JS helpers to Timber's `shop.js`
- Move login/recover password JS to Timber's `shop.js`

Demo shop for new updates - http://steve-dev.myshopify.com/

@stevebosworth @mpiotrowicz 
ah yes I remember that being a concern. A potential benefit of this is that you won't have to include a placeholder fallback JS script for older IE, since you can display the labels in old browsers instead, but otherwise aria-label should have you covered