Spawn a function hook on generational cache elimination

[jaynel]

When an oldest generation is dumped, the associated items may have related information that should be cleaned up. The delete of an ets table should be preceded by spawning a process on the list of elements in the soon to be discarded table. The newly spawned process can be more methodical about working its way through the elements (at the expense of keeping them all in memory longer).

[jaynel]

Closed wrong issue.