Requesting more messages from the Deframer causes unnecessary context-switching

In the case of a incoming stream of messages the flow-control window may accommodate more than one message. If the deframer has several messages in its currently held buffer we end up doing a lot of context switching to request more messages out as we end up with a sequence like

deframer.request(1) -> jump to app thread -> onPayload() -> call.request(1) -> jump to event loop -> deframer.request(1)