addr is set explicitly as mandatory arg
make admin telnet interface work
implement redo spooling

i.e. the redo buffer will be spooled if we have spooling
and discarded otherwise. because if you restart your endpoint
and don't have spooling enabled, don't come to us to complain
that you lost some data, so it's easier to just drop in this case

note that we needed to increase some sleeps in the test :(
maybe related because the code is a bit more intense, or because
of the extra work logging?
nicer logging

also: no need to support half-reads, remove the TODO
comment no longer needed now we have buffered chan