Allow tabbing responsive editor when not on mobile.

fixes #3095
- Add `click` event to floatingheader
Merge pull request #3098 from halfdan/3095-non-mobile-tabbing

Allow tabbing responsive editor when not on mobile.
New setup screen for blog installation.

fixes #3072
- Change router to handle /ember/setup/
- Adjust doSignup to also handle setup
- Adjust tests and add new where necessary
- Add setup controller, setup validation, setup route
- Adjust casper emberSetup to handle new setup