Text is reorganized so that most of the previous text is now in these newly-created sections:
Basic IO
Line IO
New text is added to form new sections:
Character IO
Byte IO
Codepoint IO
This gives the page a functional orientation, so that a reader can quickly find pertinent sections.
The page retains its original mission: to provide good link targets for the doc for related classes.
This page provides an overview of IO streams. It's meant to be linked to from many other doc spots. In particular it will be linked to from many places in ARGF, File, IO, and StringIO.
