Start to hook up each of the screen modules.

@borjasalguero, @sergi, @OlavHN - I have taken the code that I wrote during the Madrid work week and ported it here, attempting to follow naming conventions as much as possible. There is a lot of duplication in the modules - for instance set-password and enter-password are very similar. I did this intentionally to come up with approaches tailored to the screen and then create a generalization out of those approaches. I am not doing any lazy loading of the modules yet, but this should be possible.

I was able to simplify fxam_navigation.js a bit, and the ability to go forward and back through the states works well.

Items that still need completed:

* [ ] - Error screens for "password too short", "cannot sign in", "cannot create account".
* [ ] - Ensure swiping works. - is this a requirement?
* [ ] - Correct text needs filled in for completion screens.
* [ ] - Forgot password needs to be hooked up.
* [ ] - Centering the input elements on focus.
* [ ] - TOS/PP agreements need to be hooked up.
* [ ] - l10n of embedded strings for the interstitial screens.
* [ ] - Cleanup - is onBack needed inside of each module?
* [ ] - possible lazy loading of module JS.