Implements contents()
Added mixed text test fixture
Add test cases for .contents()
Use _.reduce() instead of a manual loop in .contents()
Added newline at end of fixtures.js
Fixed a grammar mistake in fixtures.js
Correct implementation of `$.fn.text`

This method should only act as a "getter" when the first argument is
undefined. If any other "falsey" value is specified, it should be
coerced to its String form and set as the node's text content.

The analogous logic in jQuery passes the value to the DOM
`createTextNode` method, which behaves in this way:

https://github.com/jquery/jquery/blob/2.0.3/src/manipulation.js#L35-L37
Merge pull request #260 from jugglinmike/fix-text

Correct implementation of `$.fn.text`
Release 0.12.2
Merge pull request #234 from jlep/contents

Implement .contents()
Update code style in tests

Promote consistency in usage of whitespace and semicolons.
Correct the implementation `filter` and `is`

According to the jQuery API documentation on `$.fn.filter` [1] and
`$.fn.is` [2], these methods accept any of the following argument types:

- selector string
- function
- element
- jQuery object

Extend the `$.fn.filter` method to accept elements and Cheerio
collections. This implicitly fixes the corresponding bug in `$.fn.is`.

[1]: http://api.jquery.com/filter/
[2]: http://api.jquery.com/is/
Merge pull request #266 from jugglinmike/fix-filter

Correct the implementation `filter` and `is`
Fix bug in `siblings`

The selection returned by the `siblings` method should not contain *any*
of the elements in the original selection.
Merge pull request #267 from jugglinmike/fix-siblings

Fix bug in `siblings`