TODO

. Use configuration file for default options to test() and files();
for example, it could be named .testusage, searched for in same place
as Usage.pm, $HOME; if it didn't exist, wouldn't use it.

. Allow files() to take a list of files as an argument, in addition
to/instead of the 'd' option.

. Explain what type of glob a and e match. Make the globs a bit
smarter, allowing for example 'a[123]'.

. Warn (die?) if test labels are duplicated.

. Fix running under debug: it is broken, because of the capture of the
I/O streams.

. In addition to ok(), it would be nice to have methods similar
  to the ones supplied by the other Perl Test modules, like;

  is  ($this, $that, $test_name);
  isnt($this, $that, $test_name);
  like  ($this, qr/that/, $test_name);
  unlike($this, qr/that/, $test_name);
  cmp_ok($this, '==', $that, $test_name);
  can_ok($module, @methods);
  isa_ok($object, $class);
  pass($test_name);
  fail($test_name);

      # I'd like methods like these to be generally available
      # predicates, not buried inside a test module.
  is_deeply($complex_structure1, $complex_structure2, $test_name);
  eq_array(\@this, \@that);

  SKIP: {
     skip $why, $how_many unless $have_some_feature;
     ok( foo(),       $test_name );
     is( foo(42), 23, $test_name );
  };
  TODO: {
     local $TODO = $why;
     ok( foo(),       $test_name );
     is( foo(42), 23, $test_name );
  };