Classes Details:
Default and base class for formatting a view layout. The Format
class basically defines the HTML used at the start and end of the view.
The default creates an XHTML compliant header and footer with a proper
title, and link to the stylesheet.
Format subclass that uses a template file to define the HTML header
and footer for each view.
Base class for Views. The base class provides a common interface, and
also handles common operations such as opening the file, and delegating
the view formatting to a strategy class.