add Pipe, HandlerPipe, remove HandlerList, ListenerList
Inputter: contain instead of implement ReceiverList
rename Pipe -> GenericPipe, PipeImpl -> AbstractGenericPipe
add Pipe, PipeImpl with new meaning of "listener Pipe"
Inputter.getReceiverList(): return ReceiverList, not ReceiverListImpl
ReceiverListImpl: remove propagateAll()
add RecurringTask
add FutureReceiver
add ExecutorPipe, ConcurrentPipe