Page caching

[andyjwwhite]

Page caching options should be defined in either the controller or the view class.

At the point of serving cache the Doctrine ORM should remain unloaded, so an array of related table names will need to be specified for the system to work. As the 'updated_at' field exists in every model, the system can then use one single query for all the given tables to establish the last modified date and compare against the 'If-Modified-Since' header.