Reordered material around (2.14.2), modified one reference.
Merge branch 'master' of https://github.com/HoTT/book
Proof of Thm 4.2.13 and final polish around (2.14.2)
Merge pull request #544 from marcbezem/master

Reordered material around (2.14.2), modified one reference to (2.14.2).