This is a placeholder for a partial fix of 4166799. While we can't fix that bug
in the most general possible way right now, there's no excuse for not using the
File.deleteOnExit method to delete jar_cache files whenever possible. Otherwise
we risk chewing disk space in users' temporary directories and giving them one
more reason to think that Java is flaky. Some of our partners actually deploy
applications using appletviewer, so this is not just a theoretical problem.

-- mr@eng 1998/10/9