'Equivalent to `mv old_dir/* new'

@_coerce_exceptions
def rename_star(self, old_dir, new_dir):

    if (not self.isdir(old_dir)):
        raise IOError(errno.ENOTDIR, ("'%s'    is    not    a    directory" % (old_dir,)))
    if (not self.exists(new_dir)):
        self.mkdir(new_dir)
    elif (not self.isdir(new_dir)):
        raise IOError(errno.ENOTDIR, ("'%s'    is    not    a    directory" % (new_dir,)))
    ls = self.listdir(old_dir)
    for dirent in ls:
        self.rename(HadoopFileSystem.join(old_dir, dirent), HadoopFileSystem.join(new_dir, dirent))
