Remove django-moz-header submodules.
Remove unused static files and move remained to Facebook app.
Update to latest jingo-minify.
Remove unused templates and fixtures.
Remove unused code from shared app, and fix tests.
Remove shared app and move leftovers to base app.
Update affiliates.shared imports to affiliates.base.
Fix various issues around setting up a new dev instance of the site.

- Add registration to JINGO_EXCLUDE_APPS to prevent admin logout
  template from being rendered by Jinja.

- Update signal for default permissions to abort if the
  can_share_website permission doesn't exist yet, which occurs when
  creating an admin during the initial syncdb. Also adds tests for this
  signal.

- Update install docs to have correct paths.

- Remove FacebookDebugMiddleware; Facebook app testing can be done with
  a test app, and it causes import issues.

- Add Facebook app settings for tests.
Remove django-browserid submodule.
Install latest django-browserid.
Configure site for django-browserid, add placeholder login button.
Add contributing guidelines document.