* Use disconnected() instead of readChannelFinished().
* Cleanup. There are three bidirectional pipes conceptually:
console <-> agent
agent <-> server
server <-> client
If one end of a pipe dies, start closing the other end, then clean up.
If the console dies (e.g. because cmd.exe exits), we still want to
collect the final console output and send it to the client.
To help with this, in the Agent, I call GetConsoleProcessList, then
scrapeOutput, then (potentially) disconnectFromServer.
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