[Propagable_EventProxy] Mixin has been augmented by its new [stopImmediatePropagation] method.
[Observable_SignalsAndSlots] Mixin has been refactored slightly - improved [evt] processing within [dispatchEvent] method, better internal naming and got rid of comment overhead too.
there are 3 new descendants of [Observable_SignalsAndSlots] that include support for either event propagation or for a Channels and Topics approach or, in its third variant, for both. Tests for all of them still have to be provided.