If the user copy/pasted `naughty.config.*` into their config rather
than set values 1 by 1, we could no longer add new values since they
would get removed. To prevent more users being affected by this, we
now silently ignore the new table while still setting all the values.
Fix#3145
The old preset code had a primitive implementation of the rule API
used in `naughty.dbus`. Now that `gears.matcher` is extracted from
`awful.rules`, it is possible to share the code.
The first step is to only enable the old API when the new
`request::preset` isn't connected. This is the same way the legacy
popup is only enabled when nothing is connected to `request::display`.