IoI is transport
better wording for ioi is transport
Merge pull request #641 from mikeshulman/ioi-is-transport

IoI is transport
Include new updates

Merge https://github.com/HoTT/book into uniqueness
remove name for uniqueness principle of dependent pair types
Merge branch 'uniqueness' of https://github.com/EgbertRijke/book into uniqueness