Virtualises the kick handler for the inner door in lib/pull-hook, so
that crashes in the handler do not cause a dangling resource with no
subscription. Additionally, failed kicks now cause the sync to be
dropped into a failed-kicks map in the state, where we attempt to
recover from the failure in the on-load.
If the %kick handler of the inner-core crashes, then we never get to
resubscribe, thus leaving a dangling entry in the state with no
corresponding subscription. Updates the pull-hook-action pokes to not
crash when given a dangling entry.
If we receive an %add poke for a resource we are already pulling, no-op
instead of crashing. This should prevent crashes upon repulling a
resource after a breach of the host.
