Clearer error message in replace method

Previous message was unclear for me (or I understood it wrong). It sound like I can't nest a view in already nested parent. I suppose the real meaning should be that I can't nest a child in a parent, if the child is already nested somewhere else.
Merge pull request #4915 from jembezmamy/patch-2

Clearer error message in replace method in ContainerView
single var statements which many vars that result from computation are extremely annoying to debug through.
[BUGFIX beta] Provide better debugging information.
Fix typo.
Merge pull request #4924 from ugisozols/typo

Fix typo.
[BUGFIX beta] Update backburner.js.

Update with fixes for IE8 by @tricknotes (THANKS!).
Merge pull request #4926 from rjackson/update-backburner

[BUGFIX beta] Update backburner.js.
Update jQuery version in tests.
Merge pull request #4927 from rjackson/update-jquery

Update jQuery version in tests.
[DOC beta] Fix default value of RenderBuffer's props
Merge pull request #4928 from tricknotes/render-buffer-doc

[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.
[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
Merge pull request #4929 from tricknotes/fix-for-ie8

[BUGFIX beta] Normalize HTML string for IE8
Merge pull request #4916 from rjackson/better-instrumentation-display

[BUGFIX beta] Provide better debugging information.
[bugfix] computed.alias not always equal to aliased property
Merge pull request #4930 from tricknotes/fix-collection-view-lookup

[BUGFIX beta] item/empty view should be lookuped from proper global path
[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}}`
Merge pull request #4939 from teddyzeenny/helper-debug-info

[BUGFIX beta] Add more debugging info to each, with, and unless helpers