This needs to be improved in core. Currently ClientGroup does not yet
emit signals, as it would be difficult to connect them. Nevertheless
the effects dependency should be removed.
EffectsHandlerImpl connects to the Workspace signal clientActivated.
The emitting of the signal is slightly moved from before the activation logic
to after the activation logic. This might change behavior in the scripting
component, but the previous code looked wrong.
All previously existing windowAdded methods are renamed to slotWindowAdded.
EffectsHandlerImpl is connected to Workspace's clientAdded signal, which is
emitted a little bit earlier than the previous direct method call. This might
change behavior.
Another signal is added to Workspace to signal that an unmanaged is added.
