added genport->delimted-genport
added a per-file hook to tar-unpack-genport
string-tokenize was keeping empty strings, in some cases
added snow-display-error
require less of tar-rec consumer
added genport-discard-until-eof and genport->binary-input-port
added genport-discard-until-eof and genport->binary-input-port
added genport-discard-until-eof and genport->binary-input-port