* Uses vanilla logic to decide which blocks rain falls through.
* Rain falls infinitely above the world, and stops at y=0.
* Entities will now be extinguished if they are under rain-blocking
blocks, and fire will now be extinguished by rain similarly.
* Create IsWeatherWetAtXYZ to identify wetness at a particular location.
* Use new code for enderman rain detection.
* Fixes issue #916
* Disable warnings for global constructors in the fire simulator.