resolution of symlinks in asdf

Kevin,

The change looks fine to me.  But have you checked to see if the
asdf-binary-locations system does what you need already?  I write and
run my code primarily in Allegro, but I try to test it for SBCL and
CMUCL (time permitting).  I've found that the asdf-binary-locations
system does the trick just fine for me, as is, to allow me to put my
sbcl binaries (which also end in '.fasl') in a separate location while
sharing cl source...

best,
Robert