[R6RS] Later version of original Port I/O SRFI

[Michael Sperber]

I've put the last revision I had from before Will's changes at:

http://www.deinprogramm.de/sperber/srfi/port-io-srfi.html

It wouldn't have been the final draft, but it's closer than the
withdrawn SRFI 81 draft.

-- 
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla