logging: add quiet global and cleanup logging files
Make a new global called "quiet" to replace the unknown silent that was
being passed around. Strictly speaking, "quiet" is supposed to refer only
to silently failing without warning on module load failure, but the docs
have always (erroneously) said we would also be completely silent. The
tests likewise have always assumed we will say nothing out stderr. So,
I'm just going to start treating quiet as it has been actually used.
This patch should have gone in a previous commit.
Signed-off-by: Jon Masters <jcm@jonmasters.org>