Make Ember.observer work with the function as the last argument. Support the old style with a deprecation notice.
Update tests with the new style for Ember.observer.
Update Ember.immediateObserver and Ember.beforeObserver to match the new Ember.observer style.
Updates `ember-dev` to (b0b12c4).

Updates `ember-dev` to (b0b12c4) which includes the following changes:

* Will not attempt to `unshallow` a full git repo
* Makes default test suite (packages only) run with features enabled and
  disabled.
* Fixes bug where the wrong Project name is used in the auto-generated
  CHANGELOG.
* Allows overriding the build type. (Simply set `ENV['BUILD_TYPE']='canary'`)
* Add `ember:generate_static_test_site` task to create a static HTML
  file for running the test suite.
* Add custom test results gathering for use in cross-browser testing.
* Make sure that the test file being used in the `Assetfile` is prefixed
  with the proper dasherized project name (prior to this Ember Data
  tests were still named `ember-tests.js` and now they will be
  `ember-data-tests.js`).
* Fixes issue where local `rake test` runs would attempt to perform git
  operations (`checkout` and `cherry-pick`). Now git operations will
  only be attempted if `ENV['CI']=true`.

For further reference:

https://github.com/emberjs/ember-dev/compare/0c0743979a...b0b12c4758e26
Generate static site tests.

This will publish a ember-tests.html static test site along with the
builds. This makes it extremely simple to test the latest
canary/beta/release builds on various devices. It is also critical to
the cross-browser testing that we have been working on.

This depends on changes in #3591.
Merge pull request #3592 from rjackson/static_test_generator

Generate static site tests.
Merge pull request #3591 from rjackson/update_ember-dev

Updates `ember-dev` to (b0b12c4).
Only soft-deprecate the old Ember.observer style.
Fix component name in documentation example
Merge pull request #3593 from denisnazarov/patch-2

Fix component name in documentation example
Make Ember.Error available in ember-metal.
Merge pull request #3594 from rjackson/ember_error_all_the_things

Make Ember.Error available in ember-metal.
User Ember.Error for errors.
documentation typo fixes
Merge pull request #3595 from bradoyler/patch-1

documentation typo fixes
Simplifying the observable "get" example

The "get" example referenced a method on "this" called "getEach",
which is not a method of Ember.Object.

Furthermore the signature used with "getEach" in the example does not
exist in the framework.  This can be confusing to new users.
Use consistent versioning.

Update to latest `ember-dev` and utilize a consistent version number for
all builds. This means that the version comment and the `Ember.VERSION`
constant will be the same.

The `/VERSION` file in each branches directory will indicate the next
tagged release version along with custom metadata (`+pre` for release/beta and
`+canary` for master) indicating it is a prerelease version.

See
https://github.com/emberjs/ember-dev/commit/4018355f5ee9c2dd0533e78c9cfa15dd72497096
for a more complete explanation.
Merge pull request #3603 from rjackson/use_consistent_versioning

Use consistent versioning.
Fix typo
Simplify rubygems version string.

Rubygems only supports letters, numbers, and period as part of the
version string. This uses the new structure implemented in
https://github.com/emberjs/ember.js/commit/3d8d23af6d9f1387ee37d9588bd567704730ee21
and simplifies the generated rubygems_version_string for non-published
versions.