Archivable not compatible with aggregate_column

[sam-higton]

If you have an object which is both archivable and has an aggregate column, an exception is thrown when you try to delete.

It looks like the Archive object is trying set the value of the aggregate column, but it is throwing an exception because this isn't possible.

For instance, if I have an aggregate column named "bookCount", it would throw the following exception when trying to delete:

Fatal error: Uncaught exception 'Propel\Runtime\Exception\BadMethodCallException' with message 'Call to undefined method: setBookcount.' in /home/sandbox/generated-classes/Base/AuthorArchive.php:1180

I've created an example in the Propel sandbox to illustrate this here.