Update Ghost-UI version to 0.8.1

References #3102 #2491
Merge pull request #3116 from PaulAdamDavis/master

Update Ghost-UI version to 0.8.1
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