intllib support, ported from not applied pull request to the new version

https://github.com/dmonty2/minetest-u_skinsdb/pull/1

u_skins/depends.txt

@@ -1,3 +1,4 @@
 unified_inventory
 default
 simple_skins?
+intllib?

u_skins/init.lua

@@ -2,6 +2,14 @@
 
 -- Copyright (c) 2012 cornernote, Dean Montgomery
 -- License: GPLv3
+-- Boilerplate to support localized strings if intllib mod is installed.
+local S
+if intllib then
+	S = intllib.Getter()
+else
+	S = function(s) return s end
+end
+
 u_skins = {}
 u_skins.modpath = minetest.get_modpath("u_skins")
 u_skins.file = minetest.get_worldpath().."/u_skins.mt"
@@ -62,29 +70,29 @@ unified_inventory.register_page("u_skins", {
 		
 		local formspec = ("background[0.06,0.99;7.92,7.52;ui_misc_form.png]"
 			.."image[0,.75;1,2;"..u_skins.u_skins[name].."_preview.png]"
-			.."label[6,.5;Raw texture:]"
+			.."label[6,.5;"..S("Raw texture")..":]"
 			.."image[6,1;2,1;"..u_skins.u_skins[name]..".png]")
 				
 		local meta = u_skins.meta[u_skins.u_skins[name]]
 		if meta then
 			if meta.name ~= "" then
-				formspec = formspec.."label[2,.5;Name: "..minetest.formspec_escape(meta.name).."]"
+				formspec = formspec.."label[2,.5;"..S("Name")..": "..minetest.formspec_escape(meta.name).."]"
 			end
 			if meta.author ~= "" then
-				formspec = formspec.."label[2,1;Author: "..minetest.formspec_escape(meta.author).."]"
+				formspec = formspec.."label[2,1;"..S("Author")..": "..minetest.formspec_escape(meta.author).."]"
 			end
 			if meta.license ~= "" then
-				formspec = formspec.."label[2,1.5;License: "..minetest.formspec_escape(meta.license).."]"
+				formspec = formspec.."label[2,1.5;"..S("License")..": "..minetest.formspec_escape(meta.license).."]"
 			end
 			if meta.description ~= "" then --what's that??
-				formspec = formspec.."label[2,2;Description: "..minetest.formspec_escape(meta.description).."]"
+				formspec = formspec.."label[2,2;"..S("Description")..": "..minetest.formspec_escape(meta.description).."]"
 			end
 		end
 		local page = 0
 		if u_skins.pages[name] then
 			page = u_skins.pages[name]
 		end
-		formspec = formspec .. "button[.75,3;6.5,.5;u_skins_page$"..page..";Change]"
+		formspec = formspec .. "button[.75,3;6.5,.5;u_skins_page$"..page..";"..S("Change").."]"
 		return {formspec=formspec}
 	end,
 })
@@ -131,7 +139,7 @@ u_skins.generate_pages = function(texture)
 		end
 		formspec = (formspec
 			.."button[0,3.8;1,.5;u_skins_page$"..page_prev..";<<]"
-			.."button[.75,3.8;6.5,.5;u_skins_null;Page "..page.."/"..total_pages.."]"
+			.."button[.75,3.8;6.5,.5;u_skins_null;"..S("Page").." "..page.."/"..total_pages.."]"
 			.."button[7,3.8;1,.5;u_skins_page$"..page_next..";>>]")
 		
 		unified_inventory.register_page("u_skins_page$"..(page - 1), {

u_skins/locale/de.txt

@@ -0,0 +1,9 @@
+# Translation by Xanthin
+
+Raw texture = Rohtextur
+Name = Name
+Author = Autor
+Change = Wechseln
+Page = Seite
+License = Lizenz
+Description = Beschreibung

u_skins/locale/template.txt

@@ -0,0 +1,9 @@
+# Template
+
+Raw texture = 
+Name = 
+Author = 
+Change = 
+Page = 
+License = 
+Description =