Provides a CAPTCHA for Python using the reCAPTCHA service. Does not require
any imaging libraries because the CAPTCHA is served directly from reCAPTCHA.
Also allows you to securely obfuscate emails with Mailhide. This functionality
requires pycrypto. This library requires two types of API keys. If you'd like
to use the CAPTCHA, you'll need a key from http://recaptcha.net/api/getkey.
For Mailhide, you'll need a key from http://mailhide.recaptcha.net/apikey.