Chapter 13 open for pre-reading.
Added 2014-12-24 03:04:25 +0000 UTCIt suddenly occurs to me that I have no idea if people get notified by email about these messages. That would be unfortunate https://docs.google.com/document/d/1jBl9WMiKfa8wjWtr9Whq_s1y7ZdUgRsMspT18WV1WOU/edit?usp=sharing
