Fix typo
[BUGFIX beta] Better error for content set on object
[BUGFIX beta] Still update HTML5 history if the previous state was null

Fixes #3195, Closes #3580
Uses document.contains to figure if element exists in the DOM

addresses issue raised in
https://github.com/Polymer/ShadowDOM/issues/365#issuecomment-33509711
[DOC beta] Fix a Typo in ArrayController
Merge pull request #4295 from jherdman/fix-typo-in-array-controller

Fix a Typo in ArrayController
[DOC beta] Document HTML5 attributes available.

This adds documentation to the `attributeBindings` recently added to the
`{{input}}`, `{{textarea}}`, and `{{checkbox}}` helpers.
Add 1.4.0-beta.5 to CHANGELOG.md.
Merge pull request #4296 from rjackson/doc-html5-attributes

[DOC beta] Document HTML5 attributes available.
[BUGFIX beta] HashLocation no longer looks the hash up with location.hash because of a Firefox decode bug. Fixes #4262
[FEATURE ember-routing-inherits-parent-model] Route inherits parent's model by default.
Merge pull request #4246 from locks/model-inheritance

Route inherits parent's model by default.
mark hbs code samples as such
Merge pull request #4300 from ibroadfo/patch-1

mark hbs code samples as such
Don't deoptimize every Ember.run

TryCatchStatements are currently non-optimizable statements in v8 (and likely other run times). Additionally, methods containing try/catch statements are not inlineable

Although Ember.run's shouldn't be in a tight loop, we should incur the deopt penalty if we don't even use Ember.onerror
Merge pull request #4310 from stefanpenner/dont-deopt-every-ember-run

Don't deoptimize every Ember.run
remove extra and unneeded closures.
Merge pull request #4311 from stefanpenner/reduce-closures

remove extra and unneeded closures.
remove un-needed toString
Merge pull request #4313 from stefanpenner/remove-uneeded-to-string

remove un-needed toString