Fix an issue with double ampersands breaking modern SASS compilation.

Add proper support for multiple themes and theme inheritence.

Use autoprefixer defaults.

Make sure Magento Boilerplate itself is always included.

This is not a pretty commit, but it works. Attempting to make compati…

…ble with multiple versions of nodeJS

Move conditional building of components to mixins rather than nested @…

…import statements.

Nested @import statements are not actually valid SASS, but there's a bug that's been present in (presumably) node-sass that has lately been patched, thus enforcing this. As a result, a refactor on how assets are imported was needed.

Add compatibility with the latest versions of NodeJS.

Tweaks to custom product options and price notices.

Fix compatibility with Foundation 5.5.3.

Remove customised script loading.

The "pagespeed" module, if installed, handles this better.