Add Ember.getOwner section to Factory Lookup section.

[rwjblue]

http://guides.emberjs.com/v2.1.0/applications/dependency-injection/#toc_factory-lookups

In the 2.3 guides we should also explain how to use Ember.getOwner to do the same things from within an instance of a class that was instantiated by the container. See the deprecation guide entry for a few more details.

[tomdale]

@mixonic Is this something you can tackle?

[mixonic]

I'm feeling fairly swamped by getting the actions/events stuff fixed up, sorry. Will keep it in mind though.

[mitchlloyd]

I just started using this API in an addon and I'm excited about it. I can take a shot at it today.

[rwjblue]

Awesome! Thank you!