[gnome-sudoku] Use untranslated strings in savefile.

[Parin Porecha <parinporecha src gnome org>]

commit c8ecf6660cab9f0cdb21ed4327cfb31925b4c52e
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Sat Aug 30 01:08:18 2014 +0200

    Use untranslated strings in savefile.

 lib/sudoku-board.vala |   19 +++++++++++++++++++
 lib/sudoku-saver.vala |    2 +-
 2 files changed, 20 insertions(+), 1 deletions(-)
---
diff --git a/lib/sudoku-board.vala b/lib/sudoku-board.vala
index 75fd08f..e8e2c34 100644
--- a/lib/sudoku-board.vala
+++ b/lib/sudoku-board.vala
@@ -554,6 +554,25 @@ public enum DifficultyCategory {
         }
     }
 
+    public string to_untranslated_string ()
+    {
+        switch (this)
+        {
+            case UNKNOWN:
+                return "Unknown Difficulty";
+            case EASY:
+                return "Easy Difficulty";
+            case MEDIUM:
+                return "Medium Difficulty";
+            case HARD:
+                return "Hard Difficulty";
+            case VERY_HARD:
+                return "Very Hard Difficulty";
+            default:
+                assert_not_reached ();
+        }
+    }
+
     public static DifficultyCategory from_string (string input)
     {
         switch (input)
diff --git a/lib/sudoku-saver.vala b/lib/sudoku-saver.vala
index a162ba6..c096a17 100644
--- a/lib/sudoku-saver.vala
+++ b/lib/sudoku-saver.vala
@@ -86,7 +86,7 @@ public class SudokuSaver : Object
 
         builder.begin_object ();
         builder.set_member_name ("difficulty_category");
-        builder.add_string_value (board.difficulty_category.to_string ());
+        builder.add_string_value (board.difficulty_category.to_untranslated_string ());
         builder.set_member_name ("time_elapsed");
         builder.add_double_value (game.get_total_time_played ());