Makes a subproduct filename by appending 'ext' to the subproduct directory.
        Returns a (filename,fullpath) tuple.

def subproductPath(self, ext):
        """Makes a subproduct filename by appending 'ext' to the subproduct directory.
        Returns a (filename,fullpath) tuple."""
        ext = ext.lstrip("-")
        basename = os.path.join(os.path.basename(self.dp.subproduct_dir()), ext)
        fullpath = os.path.join(self.dp.subproduct_dir(), ext)
        return basename, fullpath