closes#3153
- this is all about the validation engine
- add a option, `opts.model`, to use a passed-in model directly if needed
- handle validators that return an array of strings, array of objects, or both
- ajax util returns either an array of errors or a single concat'd string
- remove formatErrors function from the mixin and make it private
- allow validation options to be passed into `.save()` since ember-data doesn't take params on `.save()` anyway
- streamline control flow
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
