Fixed the test harness so it will write out zero-length data files.

<reply>

<data [nocheck="1"] [sendzero="yes"] [base64="yes"]>

data to be sent to the client on its request and later verified that it arrived

safely. Set the nocheck=1 to prevent the test script to verify the arrival

safely. Set nocheck="1" to prevent the test script from verifying the arrival

of this data.

If the data contains 'swsclose' anywhere within the start and end tag, and

        unlink($memdump);

    }

    # create a (possibly-empty) file before starting the test

    my @inputfile=getpart("client", "file");

    if(@inputfile) {

        # we need to generate a file before this test is invoked

    my %fileattr = getpartattr("client", "file");

    my $filename=$fileattr{'name'};

    if(@inputfile || $filename) {

        if(!$filename) {

            logmsg "ERROR: section client=>file has no name attribute\n";

            return -1;