
SIGPIPE is not handled correctly:
	If a client connects and immediately sends some data and
	the shell/command exits immediately without reading anything
	then we get a SIGPIPE when we try to write the data from the client,
	 fail to output what the shell printed and drop the connection.

	What should happen it that a SIGPIPE should disable further writes,
	 flush any data heading back towards the client, then disconnect.
	And perhaps, depending on how clients perform, send a FAILURE message
	 in response to any STDIN_DATA messages.

