way-cooler: Remove

As of 2020-01-09, way-cooler is officially dead:

    http://way-cooler.org/blog/2020/01/09/way-cooler-post-mortem.html



hence, remove the package and the module.

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

docs/release-notes: remove way-cooler

way-cooler: show warnings about removal

Apply suggestions from code review

Co-Authored-By: worldofpeace <worldofpeace@protonmail.ch>

way-cooler: add suggestion by @Infinisil