Implement stop and restart of controller/hosts (#554)

Implement remotely initiated stopping and restarting of the controller
and hosts.  Restarting is implemented by exiting with a non-zero exit
code and relying on a process manager to start the procress again.  To
prevent accidentally trying to restart on a system that doesn't have a
process manager present the --can-restart command line option needs to
be passed to enable the restart operation.

test/lib/data/SystemInfo.js

@@ -20,6 +20,7 @@ describe("lib/data/SystemInfo", function() {
 				768,
 				2048,
 				512,
+				false,
 				0,
 				false
 			);