Remove some shortcut for smileys
I think "xD" and "XD" should NOT be represented by ":D", because it's NOT the same thing AT ALL.
"XD" should stay alone (ie, don't replace it with an image), and I think it be the same for "O_o", "O_O" and "o_O".
I know I can change this in a file, but it changes only for ME, and I don't want people to believe that I want to say ":D" when I say "XD".