Implement calculating the probability for a grouped creature_text entry to trigger when converting. In EAI, the ACTION_T_TALK action type takes three parameters and all of them are creature_ai_texts entries. Basically it means it will pick one of these three (if given more than one) through randomizing. In EAI, quite some scripts use this functionality to give one text line a hihger chance to be triggered than others. So let's say we have the following parameters: '-1, -2, -2'. This means that the creature_ai_texts.entry with entry -2 now has a ~66% chance to trigger and entry -1 has a ~33% chance to trigger. With this commit this chance will be calculated and converted into the creature_text.probability field.