Close #5088 - Fix usage of document.body.contains, check if browser supports this method(ex. ff 3.6)
Deprecate Ember.Set (no, not Ember.set)
Merge pull request #5229 from trek/deprecate-ember-Set

Deprecate Ember.Set (no, not Ember.set)
jshint
Merge pull request #5243 from mixonic/jshint-navigator

jshint
Polyfill contains for older browsers
Merge pull request #5240 from trek/fix-contains-on-older-firefox

[BUGFIX release]  Fix usage of document.body.contains
refactored compare.js
nodejs apparently does not have Math.sign, also moved TYPE_ORDER to be local to compare.js
Merge pull request #5244 from adamnemecek/compare

Refactored compare.js
removed an unnecessary implementation of indexOf and moved lastIndexOf from native_array.js to array.js
refactored addArrayObserver and removeArrayObserver
moved arrayObserversHelper outside of the array mixin
Add test for more than two nested async helpers

In ember prior to commit 633cf453, if an acceptance test has more
than 2 async test helpers in an `andThen`, those later test helpers will
not fire in the proper order.

Refs #5251
Merge pull request #5252 from bantic/multiple-async-helpers-test

Add test for more than two nested async helpers
Document Brocfile
Merge pull request #5249 from rondale-sc/document_brocfile

[DOC] Document Brocfile
[DOC] Fix typos from #d8bf565
Merge pull request #5254 from chrisvariety/patch-2

[DOC] Fix typos from #d8bf565
Update Brocfile's JSHint syntax.