Fix typo
[BUGFIX beta] Better error for content set on object
[NICETHING beta] helpful whitespace classNameBindings assert

I've trolled myself many times thinking that 
classNameBindings works with a space separated string
(probably because of how bind-attr class="" works).
This should help me never troll myself again.

/cc @ebryn
[BUGFIX beta] Do not deprecate the block form of {{render}}.

Fixes #4221.
Merge pull request #4217 from machty/classnamebindings-assert

[NICETHING beta] helpful whitespace classNameBindings assert
[BUGFIX beta] reduceComputed fires observers when invalidating with undefined
Merge pull request #4210 from mmun/fix-4197

[BUGFIX beta] reduceComputed fires observers when invalidating with undefined
Merge pull request #4224 from rjackson/do-not-assert-in-render-with-block-template

[BUGFIX beta] Do not deprecate the block form of {{render}}.
Simplify code for action helper

Functionality remains exactly the same.
Merge pull request #4227 from MajorBreakfast/patch-2

Simplify code for action helper
upgrade QUnit -> 1.13.0
update backburner

included updated documentation for the run loop as well
Add templateName documentation for Ember.Route

Fixes #4234
Merge pull request #4236 from darkbaby123/master

Add templateName documentation for Ember.Route
such OCD
DRY up container tests.
Fixes #4201
[DOC beta] Cleanup outdated comment for Ember.set.
Merge pull request #4241 from rjackson/fixup-metal-property-set-docs

[DOC beta] Cleanup outdated comment for Ember.set.
Update route-recognizer

The updated route-recognizer no longer relies on Array.isArray(). Should help with IE8 compaitability.