Remove unused class fields.
Fix Verbose warning.
Fix JSON rendering for invalid JSONP requests.
#23 Get application/json test to fail.
Fixes #23

* Can now add `JsonpMediaTypeFormatter` to the end of the formatters collection.
* Support for `application/javascript` and `application/json-p`
* Added more `TestCase`s for various combinations of JSON/JSON-P co-existence
* Updated README
* Bug: UriExtensionMapping for "jsonp" now fails
Add HttpConfigurationExtensions to simplify the addition of the JsonpMediaTypeFormatter.
Address issue raised in #24 to remove other mappings in favor of matching the specified JSON-P callback parameter name in the query string.
Merge pull request #25 from panesofglass/conneg

Use QueryStringMapping matching callback parameter