Document/cleanup legacy thatch support

Eventually these XXX-marked items should be removed once the
official release has supported the newer features for long enough.

README.md

@@ -23,6 +23,7 @@ All features from WintersKnight's original NodeCore Nature mod, plus...
 		- Tall Grass -> Sedges
 		- Flowers (N.B. some colors were changed to maintain balance)
 		- Reeds -> Rushes (added dormant state)
+		- Thatch
 	- Recipe to grind vanilla dry flora into plant fibers
 	- Preserve mod flora consistent with vanilla mechanics
 - Moss Complete Overhaul

flora_mossy.lua

@@ -71,6 +71,7 @@ nodecore.register_mossy = register_mossy
 
 register_mossy("cobble", "nc_terrain:cobble")
 register_mossy("stone", "nc_terrain:stone")
+-- XXX: LEGACY PRE-THATCH SUPPORT
 register_mossy("thatch", minetest.registered_nodes["nc_flora:thatch"]
 	and "nc_flora:thatch" or modname .. ":thatch")
 register_mossy("trunk", "nc_tree:tree")

item_thatch.lua

@@ -5,11 +5,9 @@ local include, minetest, nodecore
 
 local modname = minetest.get_current_modname()
 
-local floraswap = include("lib_floraswap")
+-- ================================================================== --
-if minetest.registered_nodes["nc_flora:thatch"] then
+-- XXX: LEGACY PRE-THATCH SUPPORT
-	return floraswap(modname .. ":thatch", "nc_flora:thatch")
+if not minetest.registered_nodes["nc_flora:thatch"] then
-end
-
 	minetest.register_node(modname .. ":thatch", {
 			description = "Thatch",
 			tiles = {modname .. "_thatch.png"},
@@ -46,3 +44,10 @@ nodecore.register_craft({
 				{name = modname .. ":plant_fibers 2", count = 4, scatter = 3}
 			}
 		})
+
+	return
+end
+-- ================================================================== --
+
+local floraswap = include("lib_floraswap")
+floraswap(modname .. ":thatch", "nc_flora:thatch")