Achievements ready to be tested very gently

Git magick sparks were flying all over the place. Cherry-picked away the developer buttons I had introduced in the site's views. What we have left is a clean and test-ready achievements branch. 

What's there:
 - Achievements can be added
 - Achievements can be achieved (both unlockable and achievable)
  -> Try simulating!

What's not there:
 - You can't actually get an overview of your achievements yet
 - Achievements can not yet be retroactively applied

What's next:
 - Create an admin script that allows for recalculating achievements
 - Rework the navbar. Collapse all account buttons into something sexy. I'll get back to you with a proposed design, but I'd really like to work current level into it.
 - Work in the feedback I get of how annoyed people are to continuously see popups for simulations.