Early data and types sections do not cover material in same order as videos

[clarksmr]

The early sections of chapter 3, maybe 3.1 through 3.6, need to be edited and reordered. Tuples/records should come nearer to lists. The OUnit material can come later. There's a lack of agreement between the order that the videos (i.e. Cornell lecture slides) and the textbook cover these topics.