Some changes to depend less on `Backend` to make it easier to have additional backend implementations (ceylon/ceylon-spec#1392)
Some changes to depend less on `Backend` to make it easier to have additional backend implementations (ceylon/ceylon-spec#1392)

jvasileff/ceylon-common,ceylon/ceylon-common,jvasileff/ceylon-common,ceylon/ceylon-common,ceylon/ceylon-common,jvasileff/ceylon-common