Remove some stray commas
Reunite a long sentence
Fix a typo: "entires"
Merge pull request #364 from rwbarton/exercise-7.2

Fix a typo: "entires"
Merge pull request #362 from rwbarton/section-7.3

Section 7.3 punctuation fixes
Bring errata up to date and sort by location, #298
Merge branch 'master' of github.com:HoTT/book
minimal fix for #361
missing period
Merge branch 'master' into sumoverpaths
add 3d119cf to errata