Improve heartbeat mechanism to be able to detect when the server has "gone away" #166
Description
From @hierynomus:
"The current heartbeat implementation will send SSG_MSG_IGNORE packets to the server, unfortunately those packets are “safe to ignore” and should not be responded to. So these work fine for telling the server you’re still there, but not for finding out whether the server itself is still there."
It would be great to have a heartbeat implementation that - similar to the ServerAliveInterval and ServerAliveCountMax settings in OpenSSH - could detect when the server side of the connection has gone down.