If a connection gets through all the handshake and subsequent checks -
i.e. it ends up getting added to the LocalPeer's connection list - but
gets terminated within one minute (of the start of the successful
connection attempt), then we apply the existing backoff logic to
schedule a retry, instead of retrying immediately.
In order to do this we retain the 'Target' data structure for such
connections, marking it as 'connected' instead of deleting it (as we
did previously).
Fixes#953.
When we discover that a connection target address leads to ourself we
set the retry time to the zero time.Time value - the only special
time.Time value. We use that marker to a) suppress subsequent
connection attempts, and b) display the next retry as 'never' in
`weave status|report`.
Closes#1305.
Adam Harrison