Added Bron-Kerbosch (maximal cliques) and degeneracy ordering fns and tests.
Merge branch 'master' of https://github.com/aysylu/loom
Added Johnson's algorithm and breadth-first all-pairs shortest path and associated tests.
Fixed an error caused by finding intersection on a KeySeq rather than a Set in Bron-Kerbosch (maximal cliques).
Changed shortest-paths to all-pairs-shortest-paths.
Updated tests to refer to renamed all-pairs-shortest-paths fn.
Merge pull request #40 from mattrepl/master

Maximal cliques and all-pairs shortest path algorithms