spec: support for "codegen" generated code persistence

Some vendors would like to be able to generate code to capture
the state of a bean in the builder and create a new equivalent bean
at run-time.

This would be property-based an basically they would generate code to
new a bean and generate calls on property setters to fill in its
non-default values.

Clearly some beans have private state and need to use serialization.
But some beans can be entirely stored by their updated properties.

One possibility is that such beans might advertise their existence
by supporting an interfaces such as
      interface Codegen {
             boolean isNonDefault(String propertyName);
      }

The problem here is how to add this to existing classes, given that
an AWT class might be "codegen" persitent, but someone may have
written a derived class that requires serialization.

KGH 5/23/97