added lemon jam code, food textures

item_foods.lua

@@ -143,6 +143,12 @@ local foods = {
         source_desc = "A jar of honey",
         target_desc = "A jar of aged honey"
     },
+    lemon_jam = {
+        source = "lemon_jam",
+        target = "lemon_jam_plus",
+        source_desc = "Lemon jam",
+        target_desc = "Old lemon jam"
+    },
     melon_jam = {
         source = "melon_jam",
         target = "melon_jam_plus",