Fixup download URL for CTD. Old URL results in 403 permanent redirect, w...

Hey Michel

Here is my second attempt at a pull request, this one looks better. Rebasing on remote/origin/master helped. It looks like one of my two patches was already done by somebody else, so there is just one remaining: fixing the URL for CTD.

I'll send you more as I continue working on these

regards,
Martijn van Iersel