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 
I know we've talked labels before, but wondering why you went with this approach over the more robust version where a span inside is given the hidden styles? This way won't work in FF for example - http://juicystudio.com/article/hidden-label-firefox-bug.php