left-fold over all channel events
factories are available.
we can do generically is to close the connection. thus, most servers will actually want to implement timeouts in their service stack, producing appropriate timeout messages.
"ChannelClosingHandler" that reliably closes whatever channel it is (or will) attached to
call to .releaseExternalResources. this avoids the need for a global finagle shutdown, and allows us to keep refcounts for graceful shutdown.
service releases. this simplifies pool implementations and enhances general composability. - implement an ExpiringService that expires a wrapped service after a certain idle time.