Patch notes for v0.8.4b

Train network unload modules now default to 100% threshold (always demand) instead of 0%; load modules still default to 0%. This makes train networks work out of the box without configuring sliders. * Train dispatcher now tiebreaks between equally-good idle trains by picking the one closest to the supply station. * Improved colliders for train tracks, stations, bridges, and roads. * Improved fluid and loose train wagons 3D models to LOD popping. * Fixed that two mods both using a config.json file would fail to register. * Fixed that trains could align at the wrong module or fail to match departure conditions when the station was changed during alignment. * Fixed that two trains needing the same fuel type at the same fuel station could interfere and neither would receive fuel. * Fixed that train networks could ignore higher priority jobs in favor of lower priority ones.