core/packs/pack-files: Add diredful

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
diredful-conf.el: Configuration for diredful

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
diredful-conf: Add TODO.* to Documentation

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
diredful-conf: Remove "Hidden files"

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
diredful-conf: Remove "Hidden" too, for now

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>