Create a custom `pages` app

[bruvellu]

Currently, pages are handled by the flatpages app and custom views. This is not ideal. First, the fact that pages are created using different approaches. Second, both flatpages and custom views mix content with HTML in a way that I prefer not to. The content field in flatpages is editable, but has a lot of HTML. And in custom views, the content is written in the template, which is less than ideal for editing and updates. Furthermore, a lot of the logic to generate header variables is done in the template.

With page models in a custom pages app, I'll be able to define common variables and hook them up to different views, providing the best flexibility for generating the different pages of the project.