If we're using known-good-contract here, we won't always have an identifier for the contract, so use the contract in that case.  Also rename to contract-stx in make-with-contract-transformer so its name isn't misleading.
If we're using known-good-contract here, we won't always have an identifier
for the contract, so use the contract in that case.  Also rename to
contract-stx in make-with-contract-transformer so its name isn't misleading.

svn: r13269

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