Belligerent Occupation — Treatment of Civilian Inhabitants — Summary Execution of Civilian Inhabitants for Hostile Acts Committed against the Occupying Forces — Duty of Occupying Belligerent to Hold Proper Trial — War Crimes — Nature of — Responsibility of Occupying Belligerent for Offences Committed against Members of Own Armed Forces — Whether such Offences can Constitute War Crimes — Status of Civilian Inhabitants of Occupied Territory who Voluntarily Enlist in the Armed Forces of Occupying Belligerent — Plea of Superior Orders.