spam filter human test

[ThurnerRupert]

it would be a nice enhancement if the spam filter would do a "human test" instead of plainly rejecting an update, especially for users who state who they are. this could be done:

• via a picture (like on myspace and others), or probable even better
• via calculations which the user has to answer correctly (like on the gnu website, preferred by seeing impaired persons)

[cboos]

Please have a look at the source:sandbox/spam-filter-captcha plugin.

Duplicate of #4034.