Chainsaw: new setting to disable safe cutting

Some trees might generate with param2 != 0, which makes the
chainsaw appear blunt/useless. This safety feature is now
customizable.

settingtypes.txt

@@ -0,0 +1,9 @@
+#    Safety feature for the chainsaw tool aimed to prevent cutting structures
+#    built by players.
+#
+#    Trunk nodes generated by mapgen have a rotation of '0' whereas manually
+#    placed trunks usually have another value. However, some mods might generate
+#    trees with rotation != 0, which renders the chainsaw useless on them.
+#
+#    Disabling this feature will sacrifice safety for convenience.
+technic_safe_chainsaw (Chainsaw safety feature) bool true

technic/tools/chainsaw.lua

@@ -116,6 +116,7 @@ local cutter = {
 	-- See function cut_tree()
 }
 
+local safe_cut = minetest.settings:get_bool("technic_safe_chainsaw") ~= false
 local c_air = minetest.get_content_id("air")
 local function dig_recursive(x, y, z)
 	local i = cutter.area:index(x, y, z)
@@ -124,7 +125,7 @@ local function dig_recursive(x, y, z)
 	end
 	cutter.seen[i] = 1 -- Mark as visited
 
-	if cutter.param2[i] ~= 0 then
+	if safe_cut and cutter.param2[i] ~= 0 then
 		-- Do not dig manually placed nodes
 		-- Problem: moretrees' generated jungle trees use param2 = 2
 		return