Reformat docstrings and update some descriptions in bridgedb.HTTPServer.
Rewrite GimpCaptchaProtectedResource to use RSA & HMAC keys for verification.
fixup! Change captcha.GimpCaptcha check() and get() to use HMAC(encrypt(answer)).
Update bridgedb.crypto.getKey() docstring.
Remove unused zope imports in bridgedb.HTTPServer.
Document `request` parameter in ReCaptchaProtectedResource.getCaptchaImage().
Pep8; change `c` → `capt` in ReCaptchaProtectedResource.getCaptchaImage().
Use RSA and HMAC captcha keys in resource init in addWebServer().
Add unittests for bridgedb.captcha module.
fixup! Add crypto.getRSAKey() function.