Exercise: complete wizard example from class

Preparation: Look in the friday-24 folder, grab sse04-intermediate-updated.zip,
make it run etc.  This is the software that was the result of the Friday 24th
April lecture; to go back to the software we started with at the beginning of
the day, see description at the end of this text file.

Overview: The mail configuration wizard is complete; the wizard class and all
pages are generated, as is the abstract controller class.  The mail
configuration wizard is however not integrated with the abstract controller
class.  You can generate it from the existing page model, but it needs a
concrete subclass like color_wizard.ColorWizardControllerImpl

Approach: The concrete subclass class should implement the abstract methods from
the generated abstract controller class and the functionality from selectNext
should be moved into the appropriate, corresponding method (you should be able
to figure this out intuitively or alternatively from the original application).

Earlier version: Starting from friday-17/SSE04-wizard-v1.zip you need to add a
page model and extend the Generator class so that it can (1) generate multiple
page classes based on the page model and (2) can generate both the favorite
color and mail configuration wizards.  The page metamodel is easy to define
given that the classes are almost identical and that we can use the name of page
as command string on the button.  To solve (1) and (2) I refactored the
Generator class into an abstract Compiler class that has methods for creating
directories and writing classes etc.  For the specific case of (2) a concrete
subclass is added for each metamodel instance that we want to generate code from
(later on when we add an XML frontend it can subclass from the same class).
Last, a template for the page classes can be added, and you should now be have
functionality similar to friday-24/sse04-intermediate.zip.  To continue from
there, the selectNext method must be automatically generated to call a number of
abstract methods that define the interface between the generated code and the
manually written code.  The page model contains all the information necessary,
but a new template is needed to generate the implementation of the abstract
controller class.  Once generated an implementation has been generated, the
concrete controller class for the wizard is refactored to be a subclass of the
generated class.