Refactor `Ember.Application.initializer`.

Previously, `Ember.Application.initializers` was implemented as a
concatenated property, which is works at class definition and instance
creation time, but not when the field is mutated, which is what
`Ember.Application.initializer` was doing prior to this commit.

Also reverted concatenatedProperties change, which had been added to try
unsuccessfully to address this issue.
Fix incorrect var usage in replaceWith
Expanded comments on reopenClass

moved invalid code samples to comment (instead of JavaScript)
Revert "[BUGFIX] Fix an issue with concatenatedProperties."

This reverts commit 0158de0d05feadcf9d9b1187ff8299c966614042.
Merge pull request #3519 from ghedamat/fix-var-in-replaceWith

Fix incorrect var usage in replaceWith
remove {{debugger}} from test template
Merge branch 'pr/3516'

Conflicts:
	packages/ember-application/lib/system/application.js
	packages/ember-application/tests/system/initializers_test.js
Merge branch 'pr/3530'
[BUGFIX beta] Clean up TrackedArray.

- Remove incorrect use of "transformation"
- s/_content/_operations for clarity
- s/operation.operation/operation.type for clarity
- some crazy comment formatting
- added TrackedArray#toString.  Mostly helpful in debugging.
[BUGFIX beta] Fix edge case in `TrackedArray`.

Fixes http://jsbin.com/EFezAP/2

Fix an edge case in delete composition for a delete that right-trims an insert.
This results in a delete followed by an insert that should both compose to a
no-op, but the insert was being erroneously left behind.

Also ignore no-op adds and deletes (ie add 0 items, delete 0 items).
Merge pull request #3533 from hjdivad/fix-trackedarray-bug

[BUGFIX beta] Fix edge case in `TrackedArray`.
build rubygem beta version string correctly
Merge pull request #3515 from davidmcch/master

Expanded comments on reopenClass
remove already deprecated internal functionality
Merge pull request #3539 from stefanpenner/remove_deprecated_container_stuff

remove already deprecated internal functionality
disallow container registration if the corresponding singleton lookup has already occurred
Merge pull request #3540 from stefanpenner/throw_if_re-registering_already_looked_up_factory

disallow container registration if the corresponding singleton lookup ha...
Use plain ASCII for License.
Merge pull request #3542 from rjackson/use_ascii_in_license

Use plain ASCII for License.
Publish static test site.