There were situations, such as deleting another connection as result
of it losing a tie-break, where lifecycle events of connections on the
local peer weren't logged.
Fixing that entails moving the logging closer to (i.e. right after)
the state change action. This in turn requires promotion of logging to
the Connection interface instead of it LocalConnection. Which in turn
requires a change from 'log' to 'Log', for consistency with other
interface methods.
Fixes#449.
Matthias Radestock