From now on, all core object will have their own rules. `awful.rules`
hardcodes some client specific code. All `rules` module have some form
of class specific code. This code will now be part of a new module
called `ruled`. Since a year or so, a lot of work has been done to
refactor the rules on top of the shared `gears.matcher` class. This way
there wont be as much duplication.
This has to be in its own commit otherwise Travis will fail. This
is because it will keep the file in the build directory when
iterating all commits. Then `ldoc` will fail because the file doesn't
have documentation. If `config.ld` is updated first, then it will
fail because `ruled/init.lua` doesn't exist yet. When it is done
in a separate commit, then `config.ld` is already updated and comes
with `init.lua`.