Saplings: Reduce grow time to ABM equivalent

Previous times were chosen using statistical maths, but reports suggested
this was too long.
I tested by timing an ABM acting on 100 nodes, with interval and chance equal
to the old sapling ABM.
50 at 4m59s.
99 at 24m58s.
100 at 26m58s.
So choose a grow time between 5 and 25 min for tree and bush saplings.
If 'can grow' is false at grow time the timer is reset to 5 min.

mods/default/nodes.lua

@@ -608,7 +608,7 @@ minetest.register_node("default:sapling", {
 	sounds = default.node_sound_leaves_defaults(),
 
 	on_construct = function(pos)
-		minetest.get_node_timer(pos):start(math.random(2400,4800))
+		minetest.get_node_timer(pos):start(math.random(300, 1500))
 	end,
 
 	on_place = function(itemstack, placer, pointed_thing)
@@ -742,7 +742,7 @@ minetest.register_node("default:junglesapling", {
 	sounds = default.node_sound_leaves_defaults(),
 
 	on_construct = function(pos)
-		minetest.get_node_timer(pos):start(math.random(2400,4800))
+		minetest.get_node_timer(pos):start(math.random(300, 1500))
 	end,
 
 	on_place = function(itemstack, placer, pointed_thing)
@@ -821,7 +821,7 @@ minetest.register_node("default:pine_sapling", {
 	sounds = default.node_sound_leaves_defaults(),
 
 	on_construct = function(pos)
-		minetest.get_node_timer(pos):start(math.random(2400,4800))
+		minetest.get_node_timer(pos):start(math.random(300, 1500))
 	end,
 
 	on_place = function(itemstack, placer, pointed_thing)
@@ -901,7 +901,7 @@ minetest.register_node("default:acacia_sapling", {
 	sounds = default.node_sound_leaves_defaults(),
 
 	on_construct = function(pos)
-		minetest.get_node_timer(pos):start(math.random(2400,4800))
+		minetest.get_node_timer(pos):start(math.random(300, 1500))
 	end,
 
 	on_place = function(itemstack, placer, pointed_thing)
@@ -979,7 +979,7 @@ minetest.register_node("default:aspen_sapling", {
 	sounds = default.node_sound_leaves_defaults(),
 
 	on_construct = function(pos)
-		minetest.get_node_timer(pos):start(math.random(2400,4800))
+		minetest.get_node_timer(pos):start(math.random(300, 1500))
 	end,
 
 	on_place = function(itemstack, placer, pointed_thing)
@@ -1362,7 +1362,7 @@ minetest.register_node("default:bush_sapling", {
 	sounds = default.node_sound_leaves_defaults(),
 
 	on_construct = function(pos)
-		minetest.get_node_timer(pos):start(math.random(1200, 2400))
+		minetest.get_node_timer(pos):start(math.random(300, 1500))
 	end,
 
 	on_place = function(itemstack, placer, pointed_thing)
@@ -1433,7 +1433,7 @@ minetest.register_node("default:acacia_bush_sapling", {
 	sounds = default.node_sound_leaves_defaults(),
 
 	on_construct = function(pos)
-		minetest.get_node_timer(pos):start(math.random(1200, 2400))
+		minetest.get_node_timer(pos):start(math.random(300, 1500))
 	end,
 
 	on_place = function(itemstack, placer, pointed_thing)

mods/default/trees.lua

@@ -31,12 +31,12 @@ local function is_snow_nearby(pos)
 end
 
 
--- Sapling ABM
+-- Grow sapling
 
 function default.grow_sapling(pos)
 	if not default.can_grow(pos) then
-		-- try a bit later again
-		minetest.get_node_timer(pos):start(math.random(240, 600))
+		-- try again 5 min later
+		minetest.get_node_timer(pos):start(300)
 		return
 	end
 
@@ -94,7 +94,7 @@ minetest.register_lbm({
 			"default:pine_sapling", "default:acacia_sapling",
 			"default:aspen_sapling"},
 	action = function(pos)
-		minetest.get_node_timer(pos):start(math.random(1200, 2400))
+		minetest.get_node_timer(pos):start(math.random(300, 1500))
 	end
 })