Use Angular for navigation, and don't mix server-side and client-side templating

[lukas-shawford]

This project currently uses both client-side (angular) and server-side (Jade) templating, which results in messy code and inconsistency. I'd like to move away from server-side templating and rely more on Angular for navigation and data retrieval. Server-side templating should be limited to the main layout ("shell") page, which should just include all common scripts and stylesheets. I'm not sure whether the layout page should include the header, as that is something that might need to change down the line depending on which page you're on.

TBD: Whether to use Angular's built in angular-route, or ui-router.

To make things more consistent, I would also like to move away from using Jade as the templating engine for Express, and instead move to EJS whose syntax is more similar to HTML. While I like Jade's syntax and conciseness, I don't like the constant context-switching when working with Jade views vs HTML partials.