Enhancement: Added OnResourceAutoPublish system event

This additional system event is fired when the cache manager auto publishes a resource. This is helpful in advanced caching scenarios where you have to clean up other cache partitions when a resource is automatically published/unpublished based on pub_date or unpub_date.

Like this you can just hook in a plugin to that event to do the further cleanup instead of having to check what needs to be refreshed on every request.