Split the big "homedecor" mod into multiple sub-mods

Any of these new submods can be run without any other
components that were once part of the big "homedecor"
mod, other than homedecor_common and homedecor_i18n

Reduced dependencies where possible, but each submod still
has its various dependencies more or less the same as before,
i.e. some need basic_materials, others need unifieddyes,
some need building_blocks, and so on.

All of the stuff that used to be under homedecor/handlers
got moved to homedecor_common, as did any models and/or textures
that are used by more than one other homedecor component.

All the miscellaneous items that didn't warrant their own
mod ended up in homedecor_misc, which can also be thought
of as the remains of the original "homedecor" mod, renamed.

homedecor_common/registration.lua

@@ -0,0 +1,95 @@
+homedecor = homedecor or {}
+
+local placeholder_node = "homedecor:expansion_placeholder"
+
+--wrapper around minetest.register_node that sets sane defaults and interprets some specialized settings
+function homedecor.register(name, original_def)
+	local def = table.copy(original_def)
+
+	def.drawtype = def.drawtype
+		or (def.mesh and "mesh")
+		or (def.node_box and "nodebox")
+
+	def.paramtype = def.paramtype or "light"
+
+	-- avoid facedir for some drawtypes as they might be used internally for something else
+	-- even if undocumented
+	if not (def.drawtype == "glasslike_framed"
+		or def.drawtype == "raillike"
+		or def.drawtype == "plantlike"
+		or def.drawtype == "firelike") then
+
+		def.paramtype2 = def.paramtype2 or "facedir"
+	end
+
+	homedecor.handle_inventory(name, def, original_def)
+
+	local infotext = def.infotext
+	--def.infotext = nil -- currently used to set locked refrigerator infotexts
+
+	if infotext then
+		local on_construct = def.on_construct
+		def.on_construct = function(pos)
+			local meta = minetest.get_meta(pos)
+			meta:set_string("infotext", infotext)
+			if on_construct then on_construct(pos) end
+		end
+	end
+
+	local expand  = def.expand
+	def.expand = nil
+	local after_unexpand = def.after_unexpand
+	def.after_unexpand = nil
+
+	if expand then
+		-- dissallow rotating only half the expanded node by default
+		-- unless we know better
+		def.on_rotate = def.on_rotate
+			or (def.mesh and expand.top and screwdriver.rotate_simple)
+			or screwdriver.disallow
+
+		def.on_place = def.on_place or function(itemstack, placer, pointed_thing)
+			if expand.top then
+				return homedecor.stack_vertically(itemstack, placer, pointed_thing, itemstack:get_name(), expand.top)
+			elseif expand.right then
+				return homedecor.stack_sideways(itemstack, placer, pointed_thing, itemstack:get_name(), expand.right, true)
+			elseif expand.forward then
+				return homedecor.stack_sideways(itemstack, placer, pointed_thing, itemstack:get_name(), expand.forward, false)
+			end
+		end
+		def.after_dig_node = def.after_dig_node or function(pos, oldnode, oldmetadata, digger)
+			if expand.top and expand.forward ~= "air" then
+				local top_pos = { x=pos.x, y=pos.y+1, z=pos.z }
+				local node = minetest.get_node(top_pos).name
+				if node == expand.top or node == placeholder_node then
+					minetest.remove_node(top_pos)
+				end
+			end
+
+			local fdir = oldnode.param2
+			if not fdir or fdir > 3 then return end
+
+			if expand.right and expand.forward ~= "air" then
+				local right_pos = { x=pos.x+homedecor.fdir_to_right[fdir+1][1], y=pos.y, z=pos.z+homedecor.fdir_to_right[fdir+1][2] }
+				local node = minetest.get_node(right_pos).name
+				if node == expand.right or node == placeholder_node then
+					minetest.remove_node(right_pos)
+				end
+			end
+			if expand.forward and expand.forward ~= "air" then
+				local forward_pos = { x=pos.x+homedecor.fdir_to_fwd[fdir+1][1], y=pos.y, z=pos.z+homedecor.fdir_to_fwd[fdir+1][2] }
+				local node = minetest.get_node(forward_pos).name
+				if node == expand.forward or node == placeholder_node then
+					minetest.remove_node(forward_pos)
+				end
+			end
+
+			if after_unexpand then
+				after_unexpand(pos)
+			end
+		end
+	end
+
+	-- register the actual minetest node
+	minetest.register_node(":homedecor:" .. name, def)
+end