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 
Any reason for going with the span approach rather than title or aria-label on the inputs? With an inner span, any styles on the label element itself will still be applied and affect the layout.