CachedFastTemplate: Simple class extending CDI's Fastemplate Class

Simple class extending CDI's Fastemplate Class (www.thewebmasters.net).
Implements methods to cache pages created from documents, allowing
different pages to have assigned different cache lifetimes.
GPL'ed code (see www.fsf.org)
It requires the FastTemplate package.

[UPDATE 2000-06-07] Modified the logic to decide the validity of a cached file

(thanks to Aaron Bush <abush@microcenter.com> for some of the code and for suggestions),
and also changed the logic for the cached lifetime, allowing the use of seconds/minutes/hours/days as
units of time, which should give some more flexibility on deciding caching on
a per-file basis. The example (test.php) has been changed to reflect the changes in the
cache validation logic.

[Note] See also the Generalized CachedTemplate class that is an enhancement of this one. I will discontinue development of the class here in favor of the more generalized class approach.