* Solve problem #3 in Perl, too!
* Add explanation for Perl.
* Initial solution to Problem #4.
* Make reusable with args.
* Accept named parameters.

This is better, since if the min and max are reversed, then the function
totally breaks.
* Better usage of a parameter hash.

Damian Conway in "Perl Best Practices" believes this method is better,
since we can avoid the "uneven list" problem if a user munges the
params.
* Clean up.