When a server is told to connect to a server (with auto-discovery),
it tries to connect once. There have been a report where that
connection fails, but would probably succeed if tried again (#408).
This new parameter allows to configure the number of times a failed
implicit connect should be tried.
Resolves#408
Both seed and chained cases are now handled properly when servers
connect quickly and concurrently to one another.
When accepting a route, the server will forward the new route INFO
protocol to its known routes. In turn those routes will connect
to the new server (if not already connected).
A retry for implicit route was introduced to mitigate the issue
with two servers connecting to each other and electing the opposite
connection as the winner, resulting in both connections being dropped.
The server with smaller ID will try once to reconnect.
Some tests were fixed to handle possible extra INFO protocol.
New tests added.
Fix issue: https://github.com/nats-io/gnatsd/issues/206
