Issue #132
Changed device icons in UI:
 - green: child process controlled (started/stopped) by the UI, currently connected to the network simulator
 - red: child process controlled (started/stopped) by the UI, currently NOT connected to the network simulator (could still be running though)
 - orange: a client connected to the network simulator, but not a controlled child process. (could be an external Galileo, or maybe we’re running the VMs externally)
 - folder icon (should change to a gray icon): a node_X directory found in the network directory, but client X isn’t connected to the network simulator