Protected Attributes -> Strong Parameters

This pull request removes the protected attributes gem from the Gemfile and implements strong parameters for every resource in the project. (in addition to refactoring of many controllers and re-aliasing before filters to before action and other minor style changes)
Got it, that makes sense, a comment would be great. In terms of the mystery parameters, these are the only ones that I was confused about, so I'm thinking it shouldn't be hard to test if they're used. My guess is that by default they added both association parameters to both models, whereas you only really need `:requirement_ids` when updating a user and `:user_ids` when updating a requirement (assuming you want to edit the association on both ends). Since we only edit the association on the user side, we should only need to pass `:requirement_ids` to a user and neither to a requirement. This should definitely be verified, though, before changing.