Move sapling growing and grass adding/removing ABMs to Lua.
Fix grass adding/removing ABM.
Fix possible crash with grass ABM.
Merge remote-tracking branch 'proller/sponge' into next
Merge remote-tracking branch 'proller/weather' into next
Merge remote-tracking branch 'proller/liquid63' into next
Merge remote-tracking branch 'MirceaKitsune/moonflower' into next
Merge remote-tracking branch 'khonkhortisan/diagonal_rail' into next
Merge remote-tracking branch 'Novatux/furnace' into next
Merge remote-tracking branch 'cyisfor/master' into next
submodule add proller/minetest-mod-weather/we to mods