[R6RS] utf-16 codecs

[William D Clinger]

Kent wrote:
> Our response to ticket 68 agrees to the removal of utf-16le-codec and
> utf-16be-codec and the addition of utf-16-codec.

Yes, that is done.

I had a rough extended weekend, and do not yet have a complete
draft of the new i/o proposal.  I do have a rough draft of all
but the folding of file-options and readers/writers into port
i/o, and should be able to check that in before 1pm today.

I'm sorry to be the source of yet another delay.  The revision
involved more rewriting (and thought) than I had anticipated.

Will