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 
`timber.globalVars` only exists at the top of this file. It is instantly merged into `timber.global`, which will be used throughout the file. Not sure another way to name them the same thing without risking properties being overwritten.