node_manager_fkie: fixed echo dialog (icons, additional info)
node_manager_fkie: update launch file view after loading launch file
node_manager_fkie: fixed copy mode (Ctrl+C copy now first column, Ctrl+X: type or value)
node_manager_fkie: fixed wrong reference in sync_dialog
node_manager_fkie: fixed deleting of not reachable hosts
node_manager_fkie: added 'Do not display this warning again' button to warning message