Maxwell's puzzling demon v1.5.0

[h3]Levels update[/h3]

• Added 8-O.
  
• Fixed 8-N and A-L to prevent unintended solutions.
  
• Slightly changed 4-1, 5-18, 6-N and 6-O.
  

[h3]Other changes[/h3]

• Added "Simplified Chinese" and "Traditional Chinese" to the language settings.