Remove [apply fs] and [apply ua]

Use [apply path_forall] and [apply path_universe_uncurried] instead.
It's better practice to not name the instance when we don't have to.
Merge pull request #405 from JasonGross/remove-apply-fs-ua

Remove [apply fs] and [apply ua]
Complete is hEpi -> Contr proof using an explicitely truncated pushout.
Merge branch 'master' of github.com:HoTT/HoTT

Conflicts:
	theories/hit/epi.v
Fix proof of hEpi -> issurj using the truncated pushout.