Don't show possible numbers as a pattern by default, it's an unexpected
feature and doesn't work properly with all OSD's.

diff -up sudoku-0.2.0/setup.cpp~ sudoku-0.2.0/setup.cpp
--- sudoku-0.2.0/setup.cpp~	2008-03-22 04:00:00.000000000 +0200
+++ sudoku-0.2.0/setup.cpp	2008-03-22 13:43:53.000000000 +0200
@@ -39,7 +39,7 @@ SetupData::SetupData()
   symmetric = 1;
   mark_errors = 1;
   mark_ambiguous = 1;
-  show_possibles_pattern = 1;
+  show_possibles_pattern = 0;
   show_possibles_digits = 1;
   clear_marks = 0;
   transparency = 50;