Changed source-location->string and ->prefix to use path->relative-string/library to produce collection and planet-relative source names.
Changed source-location->string and ->prefix to use
path->relative-string/library to produce collection and planet-relative source
names.

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket