Implement lazy delegation of properties from the child to the super class.

This has better support for timestamping since we use the lower-level *_attribute methods.
Implement an override for touch because the column which we are touching might be defined in our superclass.
When saving the record, ensure that the superclass is saved also. This is necessary if the child class is not timestamped.
Set the inverse of the relations for the subclass.
Simplify the code using class_eval and a block without the need for a code text block.
Editor fail.
Remove duplicate functionality.
Merge branch 'lowjoel-paranoia-compatibility'

of https://github.com/lowjoel/acts_as_relation into lowjoel-lowjoel-paranoia-compatibility
Merge implement proper inheritance behaviour pull request