Don't forget SocketStream's or various Tokenizer's.  Buffering is a
general problem.  Specifically, we definately want to buffer at least
once, but we don't want to buffer more than once because you end up
doing extra bulk copies.

One approach would be to have a #asBufferedStream message.  For
streams that are inherently bufferend or which don't benefit from having
an extra buffer, they just return themselves.  For other streams, you'll
get a BufferingStreamWrapper which passes requests on to the underlying
stream, with buffering.  What do ya'll think?


-Lex