feat(library/data/finset/to_set.lean): add finset/set translation theorems
feat(library/data/finset/to_set.lean): add finset/set translation theorems

fpvandoorn/lean2,soonhokong/lean-windows,dselsam/lean,leanprover/lean,leanprover-community/lean,soonhokong/lean,eigengrau/lean,avigad/lean,soonhokong/lean-osx,leodemoura/lean,fpvandoorn/lean2,dselsam/lean,soonhokong/lean,levnach/lean,UlrikBuchholtz/lean,fgdorais/lean,digama0/lean,fgdorais/lean,dselsam/lean,leanprover/lean,soonhokong/lean-osx,leanprover/lean,digama0/lean,soonhokong/lean-windows,fgdorais/lean,leanprover-community/lean,fpvandoorn/lean,levnach/lean,fgdorais/lean,soonhokong/lean-osx,fpvandoorn/lean,c-cube/lean,javra/lean,fpvandoorn/lean,htzh/lean,fgdorais/lean,digama0/lean,Kha/lean,UlrikBuchholtz/lean,rlewis1988/lean,leodemoura/lean,leodemoura/lean,johoelzl/lean,avigad/lean,fpvandoorn/lean2,avigad/lean,UlrikBuchholtz/lean,htzh/lean,avigad/lean,leanprover-community/lean,fpvandoorn/lean2,soonhokong/lean,dselsam/lean,c-cube/lean,johoelzl/lean,leodemoura/lean,c-cube/lean,soonhokong/lean-windows,fpvandoorn/lean,rlewis1988/lean,rlewis1988/lean,levnach/lean,rlewis1988/lean,avigad/lean,eigengrau/lean,c-cube/lean,eigengrau/lean,digama0/lean,javra/lean,rlewis1988/lean,rlewis1988/lean,Kha/lean,leodemoura/lean,dselsam/lean,leanprover/lean,htzh/lean,htzh/lean,javra/lean,soonhokong/lean-windows,eigengrau/lean,soonhokong/lean,avigad/lean,fpvandoorn/lean,johoelzl/lean,leanprover/lean,Kha/lean,Kha/lean,sp3ctum/lean,htzh/lean,fpvandoorn/lean,leanprover-community/lean,soonhokong/lean-osx,digama0/lean,eigengrau/lean,soonhokong/lean-windows,johoelzl/lean,leodemoura/lean,fpvandoorn/lean2,c-cube/lean,johoelzl/lean,leanprover-community/lean,Kha/lean,sp3ctum/lean,sp3ctum/lean,soonhokong/lean,levnach/lean,leanprover-community/lean,sp3ctum/lean,soonhokong/lean-osx,johoelzl/lean,Kha/lean,javra/lean,javra/lean,dselsam/lean,leanprover/lean,UlrikBuchholtz/lean,levnach/lean,digama0/lean,UlrikBuchholtz/lean,sp3ctum/lean,fgdorais/lean