[Rack] i "improved" the captcha on the NB wiki

[Danny O'Brien]

It now asks one of a small set of questions when you do things like
create a new user on the noisebridge wiki. Mail me any suggested
questions with answers that are obvious to
humans but not to robots. Humans in this case must include Noisebridge
humans, who may be more robot-like than most.

https://www.noisebridge.net/index.php?title=Special:UserLogin&type=signup&returnto=Noisebridge

Bugs to http://nburl.net/bugs <-- we're running out of unfixed bugs on
this, incidentally, so start filing

d.