dynamic on the fly routing

embraced the Croogo::cache system and removed the writing of the
routes.php file. the plugin now loads routes on the fly from cache.
I also refactored the plugin to support more than the Nodes plugin. it
can now be used for a any 3rd party plugin that has a model using the
Croogo UrlBehavior.

I also changed routes to store as croogo link style strings instead of a
php array.