Feature request: automatic string decoding for writable streams

• Version: all
• Platform: n/a
• Subsystem: stream

It would be nice if Writable streams had a configuration option to decode buffers to strings (using a StringDecoder instance). This is handy for example when writing a Transform stream that takes utf8 input.

Currently you have to set up your own StringDecoder instance and write the data through that first, which is kind of annoying. For non-multibyte encodings this isn't necessary though since you can just chunk.toString() inside your _write()/_transform() handler.