switch to #lang, reindent, minor fix (when -> if), merge stuff with csu660 version
switch to #lang, reindent, minor fix (when -> if), merge stuff with csu660 version

svn: r11675

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