* Quite a few Ember-CLI / Upgrade related changes
They should all be backwards compatible. This is all to help merge our
branches.
* REFACTOR: DRY up username validation
Also avoids overwriting computed properties for compatibility with newer
Ember releases.
This reverts commit 20780a1eee.
* SECURITY: re-adds accidentally reverted commit:
03d26cd6: ensure embed_url contains valid http(s) uri
* when the merge commit e62a85cf was reverted, git chose the 2660c2e2 parent to land on
instead of the 03d26cd6 parent (which contains security fixes)
