[mcclim-devel] two fixes for graph formatting

[rpgoldman at real-time.com]

Previously format-graph-from-roots would crash if given a
:duplicate-test argument that wasn't one of the equality predicates
accepted by make-hash-table.

Previously format-graph-from-roots would crash if asked to format a
:dag.  This is fixed.  Sorta.  I'm not bragging about the dag layout
method --- it really needs a nice layering, but doesn't have one yet.
But I hope it's better than crashing!  Note that it will /still/ crash
if asked to format a general :digraph.

When I was testing this, I discovered that FORMAT-GRAPH-FROM-ROOT, the
singleton wrapper, wasn't exported from the CLIM package.  Since it's
required by the spec, I added the export, and committed package.lisp.

My first commit.  Hope I haven't gaffed anything!  Seems like the
clim-listener still works, and that's really my only test case...

Cheers,
R