[DOC] Update assertion texts for Ember.Resolver

In 7626bc81233f98c229bf9aba0b240f41ab279aff the `Ember.AbstractResolver`
has been renamed to `Ember.Resolver`, but the assertion texts where not
updated accordingly.
[Bugfix beta] Namespaces are now required to start with uppercase A-Z. Lowercase namespaces were deprecated long ago, and scanning for them was causing issues on certain Android devices.
[Bugfix beta] sync backburner

* no longer deopt during run-loop flush (due to usage of try/catch)
* workaround older IE's lack of "catch" in try/finally statement bug