How to fix arnesi:clean-op.

[73budden .]

Hi! Some new thoughts:

1. Sometimes we (developers) fail to describe system dependencies
correctly. Sometimes we just don't know the exact dependency graph.
But we feel that something is wrong with A system. Just deleting fasls
or touching the source or specific system helps to diagnose this.

2. Sometimes we want to clean system A and then reload system B which
depends on A.

3. Am I right that bug with incorrect system definition which loads
"successfully" is not fixed yet? Touching the source would help to
work around it.

These are just some reasons to extend possible use-case list of
clean-op or what whould stand for it.

>I am inclined to agree with Andreas.  I don't see that CLEAN-OP is
>impossible for ASDF.  I can see that there are some issues that require
>thought, and for some systems additional coding by the developer, but I
>don't see that as an insuperable barrier.