Acacia bush: Create a unique form different to normal bush, with more
leaf nodes at top than at base.
Acacia tree: Maximum height increased by 1 node. 2 extra nodes of
height variation.
Jungle tree: Add an extra node of height variation. Y-slices moved
downwards to be more balanced between trunk and branches, makes
branches more common.
Pine tree: Increase maximum height by 1 node. Add an extra node of
height variation.
Update sapling 'on place' protection checks for acacia and pine trees.
Biomes:
Add 'sandstone desert', 'cold desert', 'snowy grassland'.
Rename 'glacier' biome to 'icesheet' biome.
Rename non-swamp 'swamp' biomes to 'shore' biomes.
Remove 'sandstone grassland' biome.
Rename 'stone grassland' biome to 'grassland' biome.
Edit biome points for improved similarity to Whittaker classification.
Change 'tundra' to bare stone with snowblocks.
Make dirt 'swamp' / 'shore' less deep.
Ores:
Make dirt blob ore biome-specific, limit to dirt biomes.
Decorations:
Make mushroom noise spread match that of appletrees as originally intended,
to have mushrooms spawn in darker thicker forest areas.
Add coral reefs in warm oceans.
Add bushes and acacia bushes.
Jungletrees in deeper water for larger swamps.
Register flower mod decorations in singlenode mapgen for use by
minetest.generate_registered_decorations, as in default/mapgen.lua.
