use current intllib API

signs_lib/depends.txt

@@ -1 +1,3 @@
 default
+intllib?
+

signs_lib/init.lua

@@ -69,12 +69,12 @@ signs_lib.sign_post_model = {
 	}
 }
 
+-- Boilerplate to support localized strings if intllib mod is installed.
 local S
-if signs_lib.intllib_modpath then
-    dofile(signs_lib.intllib_modpath.."/intllib.lua")
-    S = intllib.Getter(minetest.get_current_modname())
+if minetest.get_modpath("intllib") then
+	S = intllib.Getter()
 else
-    S = function ( s ) return s end
+	S = function(s) return s end
 end
 signs_lib.gettext = S