//usage:#define tail_full_usage "\n\n"
//usage: "Print last 10 lines of each FILE (or stdin) to stdout.\n"
//usage: "With more than one FILE, precede each with a filename header.\n"
-//usage: "\nOptions:"
//usage: "\n -f Print data as file grows"
//usage: IF_FEATURE_FANCY_TAIL(
//usage: "\n -s SECONDS Wait SECONDS between reads with -f"