FEATURES:
* (foo|bar) should be doable.
* {$n,$m} should be doable too.
* If there was a variable, maybe $MAX_REPETITION, * could be
  implemented as {0,$MAX_REPETITION}, and + could be implemented as
  {1,$MAX_REPETITION}.  (I guess I question whether or not this would
  actually be useful, but if it isn't too hard to implement {$n,$m},
  this should be trivial.)

BUGS:
* All functions should do the right then when called in a list or
  scalar context.
* All functions should do the right then when passed either a list or
  a scalar (see last item).
* "use String::Random qw(random_string random_regex);" appears to not
  actually import anything.
