To get a feel for object-oriented programming in CLOS, we'll write a
simple database package that records information about students and the
courses they're taking.  That's Homework 3.  Homework 2 is just the
first step towards this.

Every person has a name (stored as a string).

The following functions represent the user interface to the program.

(make-person ['name "person's name"])
    creates a new person, with initial status as specified by the
    optional arguments, and returns the person object.  For
    example,
        (make-person 'name "Bloch")
    would return a person with name "Bloch".

(describe person)
    prints the person's name, using the Scheme "display" function.
    It may or may not return anything useful.

(name-of person)
    returns the person's name.

(slot-set! person 'name "new name")
    changes the person's name.  You don't have to write this one, since
    it's provided by TCLOS.