1.0.1 Release

This technical update should improve the stuttering situation and fix a number of logical errors in the game:

• Update engine. This should fix stuttering but can create other issues (thx Commander)
  
• Fix rare loophole with the map copy
  
• Fix rare bug with the _sky screen error
  
• Fix progression with the bridge in chapter 4 (thx .w)
  
• Fix lost plane door in some cases (thx Redhead)