Instead of one function that contains all the device types available in
`automation_devices` a global registry is used were each device can
register itself.
This time with a bit more though put into the design of the code, as a
result the macro should be a lot more robust.
This did result in the macro getting renamed from LuaDevice to Device as
this should be _the_ Device macro.
The attribute also got renamed from traits() to device(traits()) and the
syntax got overhauled to allow for a bit more expression.
ActionCallback now only has one generics argument that has to implement
IntoLuaMulti, this makes ActionCallback much more flexible as it no
longer always requires two arguments.
