Read time INT penalty fix

At the moment the penalty for having a lower INT then required for a book is [6 seconds * INT deficiency]. This means that regardless of book length the penalty will always be the same, and means that the penalty has virtually no effect (For a 15 minute book the penalty will be only 12 seconds with a 2 INT deficiency; only a 1.3% increase). This fixes the penalty to be dependent upon book length as the original code leads me to believe was intended, making the new penalty [6 seconds * INT deficiency * book length] and giving it an actual effect (A nice flat 10% increase in time needed for each INT short).