Documentation update and cleanup

Documentation update and cleanup

This update removes 'year' from the CD table definition in both the SQL
and in the class definition, since it wasn't being used. The directory
MyApp/Schema/ResultSet was also removed since the supplied code never
used it.

The results that the sample code produces have been expanded a little so
that they provide answers to the questions asked by the subroutine
calls.

A new section has been added that briefly discusses the results and
explains the techniques that could be used when writing this type of a
programmatic query.