Maxwell's puzzling demon v1.2.2

[h3]Levels update[/h3]

• The hint feature is now available in w4.
  
• Slightly changed 3-18, 3-18?, 3-19 and 3-H.
  
• Adjusted ?₁₄, ?₂₀, ?₂₁, ?₂₂ and ?₂₃ in w3?.
  

[h3]Other changes[/h3]

• The animation is no longer performed when redoing.
  
• Corrected some text.