[DOC beta] Fix default value of RenderBuffer's props
[BUGFIX beta] item/empty view should be lookuped from proper global path

When `itemViewClass` is given the same name as global property name,
`CollectionView` couldn't look up registered view from container.

For example:

```handlebars
<!-- index.handlebars -->
{{view App.NamesView}}
```

```javascript
App.NameView = Ember.View.extend({
  template: Ember.Handlebars.compile('hi, {{view.content}}')
});

App.NamesView = Ember.CollectionView.extend({
  itemViewClass: "name",
  content: ['tomster']
});
```

Then I expect:
```html
hi, tomster
```

But actual, the assertion error (that is referenced global property
`window.name`) is thrown.

Conflicts:
	packages_es6/ember-views/lib/views/collection_view.js
[BUGFIX beta] Normalize HTML string for IE8

This fixes are specified for IE8.

* Force HTML tag to lowercase.
* Add several `class` to be quoted
* Trim newline at the beggining of HTML tag
[bugfix] computed.alias not always equal to aliased property
[BUGFIX beta] Provide better debugging information.

Conflicts:
	packages_es6/ember-handlebars/lib/controls/text_area.js
	packages_es6/ember-handlebars/lib/controls/text_field.js
	packages_es6/ember-handlebars/lib/views/handlebars_bound_view.js
[BUGFIX beta] Add more debugging info to each, with, and unless helpers

Possible cases:

- `{{each}}`
- `{{each items}}`
- `{{each item in items}}`
- `{{unless isEdit}}`
- `{{with subject}}`
- `{{with subject as person}}`

Conflicts:
	packages_es6/ember-handlebars/lib/helpers/each.js