Added support for `CurlFile` for multipart requests to prevent deprecated warnings in PHP 5.5.

Example call:

    $client->request('POST', 'https://api.twitter.com/1.1/statuses/update_with_media.json', array(
      'status' => ‘Posting a photo’,
      'media[]' => new CurlFile(‘my-file.jpg’),
    ), true, true);
Merge branch 'curlfile-support' of https://github.com/shiki/tmhOAuth into shiki-curlfile-support
Merge branch 'shiki-curlfile-support' into dev
Support for  for multipart requests to prevent deprecated warnings in PHP 5.5. (Issue #168). Props: shiki