Rename Input to DigitalInput
Rename Delegate to DelegateBooleanParameter.

Disable some unittest during the work, will reactivate them little by
little.
Renam Notifier to ObserverSubject reference to the subject part of the
observer pattern.
Add details in commentaries.
Missing "s" in method name.
Remove useless test about SampledInput.t.h.

Remove useless inheritence form SampledInput.h.
Clean up and rename
Rename SampledInput to SimpleSampledInput
Big mess.
Wrong name, last commit before crunch.
Rename ObserverSubject to ListenerSubject.
Rename notify op'
Rename ObservableSampledInput to ListenableSampledInput
Enable old tests of ListenableSampledInput
add listenability test and behaviour.
Value of this class was discutable...
Enable inverted input test and implementation.