title: Terminate remote ssh command upon disconnect
body: <p>I'm using Mina SSHD client to run remote commands on OpenSSH server.
  I'm executing a long running command on the remote server, and would like it to terminate when the client session is closed.</p>
  
  <p>when I run this command from my PC terminal: </p>
  
  <pre><code>\#ssh -t user@server sleep 12345
  </code></pre>
  
  <p>This what I find on the remote machine:</p>
  
  <pre><code>\# ps -axf
  
  ---- Omitted for clarity
  
  12158 ?        Ss     0:29 /usr/sbin/sshd -4
  22708 ?        Ss     0:11  \\_ sshd: user@pts/3,pts/4
  16894 pts/3    Ss     0:00  |   \\_ -bash
  17750 pts/3    R+     0:00  |   |   \\_ ps -axf
  17606 pts/4    Ss+    0:00  |   \\_ sleep 12345
  
  ---- Omitted for clarity
  </code></pre>
  
  <p>when I kill the ssh client on my machine the 'sleep 12345' terminates on the remote machine.</p>
  
  <p>However when I'm running the exact same using Mina Java SSH client this what I see.</p>
  
  <pre><code>    SshClient client = SshClient.setUpDefaultClient();
      client.start();
      ConnectFuture connect = client.connect("user", "server", 22);
  
      connect.await(10000); //ms
      ClientSession session = connect.getSession();
      session.addPasswordIdentity("password");
      AuthFuture auth = session.auth();
      auth.await(10000);
  
      ClientChannel channel = session.createExecChannel("sleep 12345");
  
      OpenFuture open = channel.open();
      open.await(10000);
      Thread.sleep(15000); // ms, wait for command to run
      channel.close(true);
      session.close(true);
      client.stop();
  </code></pre>
  
  <p><br></p>
  
  <pre><code>\# ps -axf
  
  ---- Omitted for clarity
  
  27364 ?        Ss     0:00  \\_ sshd: user@pts/0  
  3277 pts/0    Ss     0:00  |   \\_ -bash
  22306 pts/0    R+     0:00  |       \\_ ps axf
  21699 ?        Ss     0:00  \\_ sshd: user@notty  
  21796 ?        Ss     0:00      \\_ sleep 12345
  
  ---- Omitted for clarity
  </code></pre>
  
  <p>after code terminates the command's parent becomes the init pid:</p>
  
  <pre><code>\# ps -axf 
  
  21796 ?        Ss     0:00 sleep 12345
  </code></pre>
  
  <p><br></p>
  
  <pre><code>\#ps -ef | grep sleep
  
  root     21796     1  0 08:26 ?        00:00:00 sleep 12345
  </code></pre>
  
  <p>Is there some flag or option in Mina to cause it to terminate my command on the remote server upon closing the session?</p>