Latest round of changes for the day - thanks again everyone.

• Added hide wall functionality - this can be done with the new button in the build panel or with the H button.
  
• Optimized NPC movement scripts for drastically better performance and FPS, especially late-game with a full town.
  
• Revised Service Rating to better accentuate staff score.
  
• Fixed bug where sometimes player could build furniture outside not meant to be outside (and would make it disappear).
  

More to come. Will also be looking at some late game balance and additional challenges next.