types/Unit
Merge remote branch 'upstream/master' into unit
types/Prod: improve the UMPs
types/Prod: products are symmetric
Merge remote branch 'upstream/master'
added a few lemmas.  "cancel" now means "unwhisker".
Merge branch 'cancel' into sigma
fix a couple things in the 'done' tactic
Merge branch 'cancel' into sigma
types/Sigma
Merge branch 'cancel'
Merge branch 'prod'
Merge branch 'sigma'
Working on HSet
Merge branch 'sigma' of https://github.com/mikeshulman/HoTT

Conflicts:
	theories/HSet.v
Merge branch 'prod' of https://github.com/mikeshulman/HoTT
Merge branch 'upstream'
Merge branch 'pull-request-1' of https://github.com/DanGrayson/HoTT into upstream
Almost finished porting HSet
Merge branch 'master' of github.com:HoTT/HoTT