I implemented scheme specific brightness settings in KPowersave. Now we need to change powersave to stop changing brightness if KPowersave is connected to prevent double setting brightness with maybe different values.

I also added a big warning message if the user try to switch to "Aggressive Powersave" scheme. By testing this message I had to notice that the DELL D600 I currently use (with preview 3) freezed and powersave died - not really funny if you try to hold the deadline. We really need more users, which test the runtime powermanagement and this new scheme.