* Activities will start reCaptchaActivity with startActivityForResult and
look for RECAPTCHA_REQUEST and RESULT_OK | RESULT_CANCELED in : 'onActivityResult()'
* ReCaptchas are implemented using a simple WebView with Javascript enable.
* All HTTP responses inside the WebView are catched (using onPageFinished())
** When Google reCatcha cookies are detected, register cookies to the
Downloader class and Return to MainActivity