Implement `$.prototype.index`
Merge pull request #528 from jugglinmike/index

Implement `$.prototype.index`
Created a wiki for companies using cheerio in production
xyz@0.4.0
Merge pull request #530 from cheeriojs/xyz

xyz@0.4.0
Move tests for `contains` method

The `api.utils.js` test file hosts the tests for all other instance
methods; there is no need for a `utilities.js` file dedicated to a
single method.
Merge pull request #532 from jugglinmike/move-tests

Move tests for `contains` method
Remove unused API method references
Remove unused variables from unit tests
Remove unused internal variables
Disallow unused variables
Remove aliases for exported methods

Prefer accessing these methods via the global `module` namespace for
clarity.
Merge pull request #533 from jugglinmike/unused

Remove unused variable references
Use JSHint's `extends` option

This allows the linting rules to be slightly more strict--test
environment globals should only be considered valid for test files.
Merge pull request #534 from jugglinmike/stricter-linting

Use JSHint's `extends` option
Complete `$.prototype.find`

Implement the two absent signatures of the `find` method.