Split the app launcher into home and tool category pages
This splits the app launcher dashboard into two types of pages:
- The homepage that shows categories of apps that are available.
- Category-specific pages that will eventually have their own applications and themes that can be launched.
There isn't any category-specific content or theming yet. There is some really basic theming infrastructure for doing this as a part of #21 (closed).
Since the old authentication interface wasn't built with the notion of logging in from any of these pages, I've temporarily disabled it. It will be reenabled as a part of #23 (closed).
Closes #20 (closed)