handle cell text properties (bold, italic, etc)

if a row 3 has 'bold' enabled before the sort, after the sort it will still be row 3 that has 'bold' enabled. 'bold' is not following the data It would be nice if at least 'bold', 'italic' and 'back-ground color' could be preserved through the sort algo

i can branch and submit the code to do that if that' ok with you