add iox subpackage

logging/doc.go

@@ -57,7 +57,7 @@ In addition. all have a ToRaw() method, which extends a Logger even further and
   - io.WriteCloser (Shutdown() on the Logger backend is called during Close(), rendering the underlying Logger unsafe to use afterwards)
   - io.StringWriter
 
-and, if stdlib io ever defines an e.g. RuneWriter (WriteRune(r rune) (n int, err error)), it will conform to that too.
+and, if stdlib io ever defines an e.g. RuneWriter (WriteRune(r rune) (n int, err error)), it will conform to that too (see (r00t2.io/goutils/iox).RuneWriter).
 Obviously this and io.ByteWriter are fairly silly, as they're intended to be high-speed throughput-optimized methods, but if you wanted to e.g.
 log every single byte on a wire as a separate log message, go ahead; I'm not your dad.
 */