Revert "[BUGFIX beta] Ember.onerror now uses Backburner's error handler - #3401"

This reverts commit 022c1f624e1a8e010f7134378f991f90c23ac523.
Merge pull request #4565 from rjackson/revert-backburner-update

Revert Backburner update due to Phantom Failures
[BUGFIX beta] Total invalidation of arrayComputed by non-array dependencies should be synchronous
Ensure run loop queues are only added once.
Merge pull request #4580 from rjackson/ensure-queues-added-once

Ensure run loop queues are only added once.
Merge pull request #4491 from selvagsz/bugfix_inject_unlooked_controller_on_controllers

[BUGFIX beta] Fix `Maximum call stack size exceeded` error when injecting un-lookup'd controller on controllers
[DOC] Improve register/inject documentation
Merge pull request #4577 from mixonic/improve-register-inject

[DOC] Improve register/inject documentation
dragOver was missing
Minor fix for to detect `find` method

Fixes #4583
Merge pull request #4478 from bradfol/doc-actionhandler

[DOC] Correction for `ActionHandler` implementing classes
Merge pull request #4563 from kalmanh/patch-1

Minor documentation update: Update enumerable_utils.js
Cleanup unused var
ES6 ember-application
Merge pull request #4584 from twokul/model-find

Minor fix for `find` method
[BUGFIX beta] #4474 - Assertion when using 'basic' as a route or resource name.

[BUGFIX beta] #4474 - Assertion when using 'basic' as a route or resource name.

Foo

Foo
Merge pull request #4475 from gordonkristan/master

[BUGFIX beta] Potential solution for #4474.
Merge pull request #4591 from trek/es6-ember-application

ES6 ember-application
Nicer structure for String utility helpers
Fix exports from ES6ing of ember-application.

Fixes #4593.