Update 0.45

The worlds are twice larger now, 4 times the area. With optimizations, it looks like they'll be fine for the multiplayer.

Change log:

• Game worlds are now 4 times the area than before. Fog range is the same, so you can only see about quarter of the world around you now.
  
• Optimized fluid simulation.
  
• Many optimizations in world generation.
  
• Added (slightly) animated loading screen, long tasks like world generation now run in background.
  
• Added anonymous game analytics. For now it only records simple events like starting a new game, and sends crash logs to the developer.