New typography hierarchy

This is a big commit I know :frowning: 

Part of the style-guide refractoring work we are carrying out was to add the new global type scale and baseline grid that the designers have been working on for the last two weeks.

The new typography styles can be found on the style-guide here:
http://developme-stylegui-1vcqaf33tm1nk-926292852.eu-west-1.elb.amazonaws.com/style-guide/typography

This pull request changes all of the type size and line-height on the whole site, hence many files have changed. It is only aesthetics though and no Scala has been harmed in the process.

The pull includes:

- Removed the apps dependency on pasteup.css
- New stylesheet folder structure
- New type classes and mixin
- Changes type class attribute on most modules

The reason why we are merge this now is to avoid an even bigger pull request with whole style-guide in January.

Happy commenting :cactus: