Merge: lib: add IStream::read_lines

Lines are not chomped since I prefer to not lose information.

Pull-Request: #960
Reviewed-by: Alexandre Terrasa <alexandre@moz-code.org>
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>