split signs_lib from homedecor, put them into their own separate mods

package the two together as a modpack so that regular homedecor users don't
see a functional change, but others can take signs_lib and use it as a
standalone mod.

also get rid of some *~ files

homedecor/shutters.lua

@@ -0,0 +1,43 @@
+-- Various kinds of window shutters
+
+local S = homedecor.gettext
+
+local shutters = {
+	{"oak", "Unpainted oak"},
+	{"mahogany", "Mahogany"},
+	{"red", "Red"},
+	{"yellow", "Yellow"},
+	{"forest_green", "Forest green"},
+	{"light_blue", "Light blue"},
+	{"violet", "Violet"},
+	{"black", "Black"},
+	{"dark_grey", "Dark grey"},
+	{"grey", "Grey"},
+	{"white", "White"},
+}
+
+for i in ipairs(shutters) do
+	local name = shutters[i][1]
+	local desc = shutters[i][2]
+
+	minetest.register_node("homedecor:shutter_"..name, {
+		description = S("Wooden Shutter ("..desc..")"),
+		tiles = { "homedecor_window_shutter_"..name..".png" },
+		inventory_image = "homedecor_window_shutter_"..name..".png",
+		wield_image = "homedecor_window_shutter_"..name..".png",
+		drawtype = 'signlike',
+		sunlight_propagates = true,
+		paramtype = "light",
+		paramtype2 = "facedir",
+		walkable = false,
+		groups = { snappy = 3 },
+		sounds = default.node_sound_wood_defaults(),
+		paramtype2 = 'wallmounted',
+		selection_box = {
+			type = "wallmounted",
+			--wall_side = = <default>
+		},
+	})
+end
+
+minetest.register_alias("homedecor:shutter_purple", "homedecor:shutter_violet")