remove redundant assignment of isDestroyed
Update for Handlebars 1.1
[DOC release] Add Ember.Application.testHelper documentation.
[FEATURE ember-testing-lazy-routing]

* `setupForTesting` sets the application into testing mode (which is
  used to defer readiness.
* Adds an initializer that defers readiness if the application is in
  testing mode.
* `visit` helper has been updated to advance readiness upon first call.
* `App.reset()` now behaves the same after `setupForTesting` (in a
  deferred state).
Merge pull request #3692 from rjackson/add_test_helpers_docs

[DOC release] Add Ember.Application.testHelper documentation.
Merge pull request #3695 from rjackson/defer_readiness_in_initializer

[FEATURE ember-testing-lazy-routing]
Renaming everyBy and anyBy to isEvery and isAny
Merge pull request #3662 from twokul/everyBy

Renaming everyBy and anyBy to isEvery and isAny
Support HANDLEBARS_PATH for Gemfile

This makes it easier for Ember's tests to be run against a
development version of Handlebars.
[DOC] Add ember-testing-lazy-routing to FEATURES.md.
Merge pull request #3697 from rjackson/add_docs_for_lazy_routing

[DOC] Add ember-testing-lazy-routing to FEATURES.md.
[DOC] Add reference for ember-routing-named-substates.
Merge pull request #3682 from rjackson/features_update

[DOC] Add reference for ember-routing-named-substates.
remove registerFactory doc reference (its all just register now)
[BUGFIX release] Fix #3681.

`Em.arrayComputed` is not presently compatible with lazy CPs. There are a few
issues.

1.  To keep refs up to date, observers stay around as long as the object does.
2.  Those observers can repopulate the cache, but when they do so they fail to
    add dependent keys when the cache was empty.

This commit works around 2. by not removing them in the first place.
Essentially the semantics for `ArrayComputedProperty`s differ from standard
`ComputedProperty`s with regards to laziness.

These observers need to be managed better.  Probably the right thing to do, now
that `recomputeOnce` is no longer necessary, is to:
  1. Fix `Em.computed.sort` to not use `recomputeOnce`;
  2. Fix `Em.arrayComputed` to return a proxy to the cached value;
  3. Teardown array observers when the deps count hits 0.

This will give reduce computed properties semantics much closer to regular
computed properties.  There are two important points to note about this
suggestion:

1.  The cached values would still update synchronously.  This can be improved
    with a lazy array implementation and @wycats's skiplist strategy.
2.  The semantics of an array computed would change such that existing refs
    would only be kept up to date as long as the cache had not been invalidated.
    This is probably fine: the current behaviour is not promised in the
    documentation anywhere and it would be pretty bad practice to keep
    references around rather than `Ember.get`ing them.
[BUGFIX beta] The router should cleanup itself upon destroy.

Prior to this change the router did not cleanup its location object upon
destroy. This caused multiple transitions to be triggered after an
`App.reset()` call.

Resolves #3669.

@twokul / @rjackson
[BUGFIX beta] Correct `Em.typeOf` docs re: boxed types.
Remove unused local var from link_to test
Merge pull request #3710 from balinterdi/remove-unused-snippet-from-link-to-test

Remove unused local var from link_to test
Merge pull request #3708 from hjdivad/doc-typeof

Correct `Em.typeOf` docs re: boxed types.