Find a better CSS and JS structure that allows for not having ALL CSS and JS on ALL pages

[halvardos]

Points to consider with JS:

• The theme should encourage use of OO ES6. through transpiling with babel.js.
• Encourage / force good code style with ESlint (https://github.com/airbnb/javascript/tree/master/packages/eslint-config-airbnb) (4 spaces)
• Selective loading of scripts.
• Possible mapping to es6 files.
• Development files that are not minified
• Head / footer loading?
• Encourage / exemplify good file structure.