Au Naturel

Minor update:
- Includes new falling water mod: cannot swim up waterfalls and running water, and will drown (or more accurately, sink) if you attempt to swim with an armour encumberance effect active.  Can still ride in a boat though, just don't fall out.

- Internal updates to c2me and distant horizons: an attempt to prioritise gameplay performance over raw throughput. scale throughput and settings appropraite for different computesr and platforms rather than set one config for all.

Attempt to always have some prioritised worker for loading player adjacent chunks, preference reads over writes, and generally make things smoother overall.  Distant horizon change prioritisation, make things generally smoother, and other general improvements.

- Added minor documentation for falling water to au naturel res pack