Make isequiv_homotopic show up in [SearchAbout IsEquiv pointwise_paths]
Merge pull request #318 from JasonGross/isequiv-homotopic

Make isequiv_homotopic show up in [SearchAbout IsEquiv pointwise_paths]
Merge pull request #316 from JasonGross/ex-3-13-3-14

I am assuming a single pair of eyes is ok for this.
Do most of Exercise 4.5

I'm still not sure how to give a higher-level proof of [IsEquiv f ->
IsEquiv (ap f)].  Also, I'm not sure if the [Proof with typeclasses
eauto.] and [...] are appropriate for HoTTBookExercises.