Plague 3.12 - fun and speedy changes abound

• optimised connected sets algorithm to calculate optimal cells only – builds maps faster 
  
• made CA_tech demo more fun by letting player burn stuff and delete rocks, etc. 
  
• “easter egg”: press “o” on the main screen for the test map. You can deposit stuff using numpad keys. Fun for making your own map and populating with soldiers, zombies, ammo, etc. 
  
• Renamed Connected_sets to Partitions 
  
• made zombie_normal slightly slower 
  
• made zombie_massive turn slightly slower 
  
• made bullet currently_penetrating only for blocking sims 
  
• fixed logical error in bullet_collision. Bullets now interact with more than the first sim (eg: sniper rifle bullets kills MULTIPLE zombies in one shot).