Replaced most uses of get_modpath() with variables cached at the top of init.lua

door_models.lua

@@ -1,8 +1,8 @@
 
 -- Boilerplate to support localized strings if intllib mod is installed.
 local S
-if (minetest.get_modpath("intllib")) then
-    dofile(minetest.get_modpath("intllib").."/intllib.lua")
+if intllib_modpath then
+    dofile(intllib_modpath.."/intllib.lua")
     S = intllib.Getter(minetest.get_current_modname())
 else
     S = function ( s ) return s end