Fix promise rejection

fixes #3013
- bubble promise rejection on post model validation/save error so that it doesn't bubble as resolved
- prefer `.catch()` for promise handlers as per recommendations
- check if `.save()` is being called from model.destroyRecord() and forgo validation if so
- normalize output for both `.validate()` and `.save()`
Fix word count in ember.
Merge pull request #3023 from darvelo/promise-rejection

Fix promise rejection during validation
Merge pull request #3033 from halfdan/fix-word-count

Fix word count in ember.
Adding more ember admin tests

- improving the implementation of thenOpenAndWaitForPageLoad
- adding a class into the settings templates to more easily test which pane we are on
- adding more, and updating more of the settings tests
- added the editor tests