add Ember.computed.defaultTo
Fix render helper with model when used multiple times
Return merged object from Ember.merge
Add `pattern` to document about binding property

`Ember.TextField` supports `pattern` as its binding property.
Merge pull request #2290 from tricknotes/fix-doc

Add `pattern` to document about binding property
Fix document indent
Merge pull request #2291 from tricknotes/fix-document-indent

Fix document indent
Use `function.call` instead of `function.apply`

The former is faster than latter in a lot of cases.
Remove unused variable
Merge pull request #2292 from tricknotes/use-call-instead-of-apply

Use `function.call` instead of `function.apply`
Merge pull request #2293 from tricknotes/remove-unused

Remove unused variable
Refactor of Ember.Application's way of resolving objects looked up in the container. These changes allow the app to specify a resolver class and make it possible to plug in alternate approaches or augment the default approaches.
Merge pull request #2287 from lukemelia/pluggable_resolver

Refactor of Ember.Application's way of resolving objects
No longer special case app init for testing:

https://github.com/emberjs/ember.js/blob/master/packages/ember-application/lib/system/application.js#L313 actually makes app boot deterministic.
Fill in a missing test (and fix) for resolving a normal (non-controller or template) object.
Merge pull request #2296 from lukemelia/fix-new-resolver-for-normal-classes

Fill in a missing test (and fix) for resolving a normal (non-controller or template) object.
Merge pull request #2289 from stefanpenner/removeUneededTestingFlags

No longer special case app init for testing:
Added isDestroying/isDestroyed flags meaning and invariants docs.
Enumerable#compact now removes undefined values
Merge pull request #2303 from valentin-nemcev/enumerable-compacts-undefined

Enumerable#compact now removes undefined values