cl-numlib, array-operations and cl-colors migrated to Github; my packages are asdf-installable again

Looks like I goofed up when releasing cl-2d: it used a few routines which were sitting on my hard disk but not made public yet. I think I corrected that, and pushed the new versions to Github. Also, I think I figured out how to link to tarballs on Github. Using entries like

:(package "http://github.com/tpapp/cl-2d/tarball/master")

ASDF goes to Github, where is it redirected to the latest master tarball, and appears to work fine. If not, let me know and it will be fixed. Still, I would suggest that you use git to keep updating the libraries if you can. Thanks to Peter Mikula for reporting the missing library code.