Also add meta attributes and a wrapper for jing so that it can be
invoked directly from the shell as "jing" (similar to Debian/Ubuntu).
Trang already has such a wrapper.
URLs to http://nix.cs.uu.nl/dist/tarballs. With content-addressable
mirror support (r9190, NIXPKGS-70) this is no longer necessary:
fetchurl will try to download from that location automatically. So
we can keep the original URLs.
svn path=/nixpkgs/trunk/; revision=9192