Initial work on traversable
Add File.Stream and Stream.into/3
Add IO.Stream as well
Add traversable to bootstrap
Use raw modes for File.write/2 and File.Stream
Ensure an after clause is generated only if required
Update char list samples in IO tests
Rename Traversable to Collectable
Rename Traversable to Collectable
Merge pull request #2093 from elixir-lang/jv-into

Add support for Collectables