Clean up some ember-metal chains code

1. The first change removes a weird instance of 
   improperly removing nodes from an array which
   would break in case there’s every a time that
   a node appears in the array more than once
   (but I’m pretty certain this is never the case)
2. Removed unnecessary .length check of 
   (str && str.length > 0)
Allow passing computed ES6 modules to #view.

Right now, it's possible to pass a computed property to the {{view}}
helper, but that only works if the property returns an `Ember.View`.

This change allows the computed property to return a string, which
the helper will now try to interpret as an ES6 module and resolve.
Merge pull request #4975 from drwrf/refactor/view-resolution

Allow passing computed ES6 modules to {{view}}.
[BUGFIX beta] Filter models in the data adapter when looping over namespaces
[Bugfix] ensure RSVP.on(‘error is correctly unsubscribed
Merge pull request #4978 from stefanpenner/rsvp

[Bugfix] ensure RSVP.on(‘error is correctly unsubscribed
Merge pull request #4977 from teddyzeenny/filter-models

[BUGFIX beta] Filter models in the data adapter when looping over namespaces
Merge pull request #4969 from machty/clean-chain

Clean up some ember-metal chains code
Fix components inside group helper

Components (like `link-to`) end up with the wrong context when used
inside a `#group` helper. And their templates don't get grouped.

I understand that #group is experimental, but as long as the support for
it remains in master, it makes sense to not leave it broken.
Merge pull request #4957 from ef4/grouped-component

Fix components inside group helper
[BUGFIX beta] Route#modelFor shouldn't rely on router

This is especially useful for unit testing. In cases where
there is no router, `modelFor` will no longer cause an exception.
use ember-cli as the CLI to build ember. (broccoli under the hood)

Such dog-fooding.

bonus, ember-cli now comes with  broccoli-sane-watcher, which dramatically reduces the cost of file system watching.

Enjoy your battery life!
Merge pull request #4982 from stefanpenner/ember-cli

use ember-cli as the CLI to build ember. (broccoli under the hood)
Cleanup ember-cli transition.
Use qunit-phantom-runner from bower.
Merge pull request #4983 from rjackson/fixes-for-ember-cli-usage

Build system cleanup.
Ensure that min + prod files are generated properly.
Merge pull request #4986 from rjackson/moar-cleanup

Ensure that min + prod files are generated properly.
Replaces single multiline var statement with multiple var statements
Merge pull request #4987 from locks/patch-1

Replaces single multiline var statement with multiple var statements