&meeseengine Voxel engine for PC

I downgraded my PC to an office laptop with integrated graphics, and my voxel engine still runs at 60 FPS with a render distance of 64. After a major I/O system overhaul, it's now 9x faster than before. To put it in perspective:

• The latest build is 700x faster than some competing voxel engines.
• Even the older version was already 78x faster.
  World loading is near-instant. See #project-discussion for competitor comparison.