Make promise.ss use #%kernel directly -- this way mzscheme does not depend on scheme/base.
Make promise.ss use #%kernel directly -- this way mzscheme does not
depend on scheme/base.

svn: r10424

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