Merge pull request #2648 from teddyzeenny/object-observable

Fix docs to use extend instead of create when setting observers
Replace Ember.RunLoop with Backburner.js
Revert "Replace Ember.RunLoop with Backburner.js"

This reverts commit a8b6e3042244af1dd315e94c9349722450bca301.
Fix test module name

This module is 'sync_test' not 'schedule_test'.
Remove unused variables and helper function
Rewrite `EMBER_VERSION` with `Ember::VERSION`

This commit is leak of 451f24c4.
Merge pull request #2654 from tricknotes/rewrite-constant-for-ember-version

Rewrite `EMBER_VERSION` with `Ember::VERSION`
Merge pull request #2653 from tricknotes/remove-unused

Remove unused variables and helper function
Merge pull request #2652 from tricknotes/fix-test-module-name

Fix test module name
Ember testing capture exceptions thrown in promises