A Few Small Things

This is a pretty small update, so the list of improvements is quite short:

• Adjustments to levels 80 and 85 to avoid unintended solutions.
• Correction of typo in level 80.
• It is no longer possible to look around during level transition if the menu is open. 
• Closing the menu with the esc-button works during level transitions, too.
• Adjustment to level 23 to prevent people from reaching a messed up/unsolvable state. It is still possible to mess up the level. However, with the changes messed up states should only be reachable if the player tries hard and intentionally to do so.