AdapterPopulatedRecordArray triggers `didLoad` event at the end of the runLoooop

- Fixed reported integration tests
- Add Em.run to some tests which became invalid with this change
Warn when using `reference` as an attribute name

It would be much better to use `_reference`, I'll see if I can work that out and add another commit.
Rename 'reference' on record to '_reference'
Merge pull request #596 from sandstrom/patch-1

Use _reference instead of reference for DS.Model
Merge pull request #589 from sly7-7/adapter-remove-dead-code

remove dead code in adapter since data extraction is done in the seriali...
Remove inaccurate information from README.

This truncates the README considerably, but considering the previous
version was months out of date, it wasn't being helpful to newcomers.

A reference to the guide and its correctness at version 11 is added.
Only setting content-type to JSON if there actually is content.
Merge pull request #581 from Mochaleaf/enumTransform

Adding support for registering enumerated types in a more straightforward way
This allow to define integer ids in the fixtures, as well as integers

correct test title
Merge pull request #575 from shwoodard/breaking-changes-typo

fixing documentation typo - missing close array
Merge pull request #597 from trek/shorten-readme

Remove inaccurate information from README.
Merge pull request #564 from jefflab/null-belongsTo

cover null case for belongsTo relationship
Formatting
Breaking changes.md update

- Added note about Adapter.configure for side loading
- Added a note about dirtying record changes
Merge pull request #613 from Mochaleaf/breaking_changes

Breaking changes.md update
Merge pull request #521 from mspisars/fix_model_setup

Rename setup() method to _setup() on DS.Model
Merge pull request #538 from yourkarma/ie8-date-transform

Fix issues with parsing ISO 8601 dates in IE8
Make DS.RESTAdapter default adapter of DS.Store
Add a space in the assertion message
Merge pull request #615 from Myslik/master

Make DS.RESTAdapter default adapter of DS.Store