Uses the HTTPS url for cases where the existing URL has a permanent
redirect. For each domain, at least one fixed derivation URL was
downloaded to test the domain is properly serving downloads.
Also fixes jbake source URL, which was broken.
Old package expression had two problems:
* source download link was broken
* when working, it downloaded almost 400 MB of data because it cloned
the entire mercurial repo, via http it's only about 140 MB.
[Bjørn: extend commit message]
Basically it builds, but I still don't know how to run it. I imagine the
installPhase is still too poor, but it's better than nothing.
I also added two mygui versions. That stable, and that required by Rigs of Roads (svn).
svn path=/nixpkgs/trunk/; revision=26618