[PythonCE] Spam on the wiki

[alexandre.delattre at enst-bretagne.fr]

Once again the PythonCE Wiki was spammed, fortunately no data seems to  
be lost, and with the history feature it should be easy to revert  
back. I'am almost sure the modifications are done by a web bot not a  
human person. Luke, would it be easy to use a captcha system in the  
Wiki (when creating an account, or editing a page) ?
Could you also close the accounts of the users who posted the spam ?

Any ideas suggestions to prevent spamming is welcome.

Alexandre.