Please add cl-digraph

[sjl]

cl-digraph is an implementation of a directed graph data structure. I got tired of reimplementing half-assed DAGs after the fourth time and made a library. More info is in the README and docs.

Builds with no warnings in SBCL on OS X and Debian. Test suite passes in SBCL, CCL, ECL, and ABCL on OS X and Debian. It should build/run on other OSes/implementations too -- I haven't tried.
License is MIT/X11.

Mercurial: https://bitbucket.org/sjl/cl-digraph/
Git mirror: https://github.com/sjl/cl-digraph/

Either one is fine to use as the source, they should be identical.

Thanks.

[quicklisp]

This doesn't build due to a reference to the QL package, which isn't present in the test build environment.

[sjl]

Quicklisp doesn't have quicklisp? Okay, I removed the reference, it was just an old debugging function anyway.