[plt-dev] Module browser change

I have committed a change to the module browser: requires for a file
that is local to the same "library" are always shown, even if the
require is using a symbolic name or (planet ...).  This means that if
you're working on a plt collection and open the module browser, you'll
see your library's files even if you choose to hide lib requires, and
the same for planet.

(For now, the concept of what directory is considered a library is
currently hard-wired as a subdirectory of one of the collection roots,
or four levels down from the planet cache.)

-- 
          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                  http://www.barzilay.org/                 Maze is Life!