Merge pull request #2594 from twokul/master

restore defaultContainer for now, but deprecate it
default input helper to type="text" if no type given
fix defaultContainer deprecation warnings.
Merge pull request #2598 from fivetanley/default-input-type-is-text

default input helper to type="text" if no type given
Adds disabledWhen option to {{linkTo}} helper
Merge pull request #2600 from stefanpenner/fixup_deprecation_warnings

fix defaultContainer deprecation warnings.
Merge pull request #2436 from trek/disabled-linkto

Adds disabledWhen option to {{linkTo}} helper
More accurate, helpful error message for handlebars version errors.
Merge pull request #2602 from mixonic/explicit-version-matching

More accurate, helpful error message for handlebars version errors.
Don't add disabled class if disabledWhen not provided
Merge pull request #2607 from bradleypriest/disabledWhen

Don't add disabled class if disabledWhen not provided
Improve {{render}} docs.

Updated to clarify the different behavior when passing a single argument
versus two arguments.
Merge pull request #2609 from lukemelia/improve-render-docs

Improve {{render}} docs.
Remove duplicated test.
Update variable names in a test for #each to be less confusing.

This test has nothing to do with the itemController option.
Create Ember.Test with registerHelper method
Add onInjectHelpers method
Include `Ember::VERSION` in 'ember-source' gem

For examples:

``` ruby
require 'ember/source'

Ember::VERSION #=> "1.0.0-rc3"
```
Use helper function

`append` is defined for append `checkboxView` to '#qunit-fixture'.
Stop unnecessary `jQuery.fn` extension

I replaced jQeury methods to helper functions.