use class to dictate which fields are required

abstracted JS out of template
Merge branch 'validations'
moved form labels to placeholders
WIP: addons
create unique path for advanced_form.js
changing dir where assets are served from
WIP: assets
fixed paths for serving assets
WIP: breakpoints for advanced form
remove descriptors for add-ons
adjusted form fields at various breakpoints
use Handlebars for add-on templates
WIP: format add-on price
Merge pull request #2 from chrissrogers/adam/advanced-form

Adam/advanced form