preventing spam on openEHR wiki

Dear all,

we have enabled the 'captcha' mechanism on the openEHR wiki, due to
spamming in the form of comments on some pages. This will mean that to
create comments you now either need to be logged in or else you are
going to be challenged with a dialogue designed to determine if you are
a human rather than a spambot of some kind. Sadly nothing appears to be
safe from the mentally bereft.
- thomas beale