Moved the connect to Peer logic from the Node to the Peer to fix a possible race condition causing a node to slowly be disconnected from the network. There might still persist some issues with even connected nodes that are not accessible. The ~90min reconnect should fix this.
Merge remote-tracking branch 'origin/master'
Added a _flusing flag to Peer to monitor for possible congestion of the async_write call in flush() - in boost it is disallowed to call it multiple times.