Fix dead ongen saplings due to biome_lib secession (#35)

* Replaced print with minetest.log in init.lua

* Added moretrees_ongen group to ongen saplings

* Added LBM and setting to enable it for non-functional ongen saplings due to biome_lib secession

* Changed LBM run_at_every_load to true

* Fixed luacheck warnings

* Using random interval for node timer, like in the on_generated timer interval

* Update init.lua

* Update node_defs.lua

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Co-authored-by: Niklp <nik@niklp.net>

settings.lua

@@ -74,6 +74,10 @@ moretrees.dates_item_drop_ichance	= tonumber(stg:get("moretrees.dates_item_drop_
 moretrees.sapling_interval		= 100
 moretrees.sapling_chance		= 5
 
+-- Enable this only if you have used an old moretrees version which was using biome_lib
+-- and when you notice large areas with ongen saplings that don't grow
+moretrees.grow_legacy_saplings	= stg:get_bool("moretrees.grow_legacy_saplings", false)
+
 -- If this variable is set to true, drop leaves out as entities during leaf
 -- decay, rather than just disappearing them.
 moretrees.decay_leaves_as_items = stg:get_bool("moretrees.decay_leaves_as_items", false)