Introduced a new io.Content class, with Content.Source, Content.Sink and Content.Chunk.
Updated the server-side to use io.Content instead of the previous server-side Content class.
Updated the client-side to use io.Content with a little specialization necessary for clients only.
Signed-off-by: Simone Bordet <simone.bordet@gmail.com>
Co-authored-by: Ludovic Orban <lorban@bitronix.be>