Comment and white-space cleanup in IO libraries.

Comment and white-space cleanup in IO libraries.

- use dart doc comment for interface comments.
- use '//' style comments for non-doc comments.
- remove some whitespace.

R=whesse@google.com
BUG=
TEST=

Committed: https://code.google.com/p/dart/source/detail?r=3554

[Bill Hesse, 2012-01-24 15:37:49]

LGTM.

It seems wrong that we can't use Dartdoc on implementation files, unless we want
to publish the interface.  We should work on a better way of selecting what to
publish, so we can have internal files with Dartdoc comments.

[Mads Ager (google), 2012-01-24 15:39:02]

On 2012/01/24 15:37:49, Bill Hesse wrote:
> LGTM.
> 
> It seems wrong that we can't use Dartdoc on implementation files, unless we
want
> to publish the interface.  We should work on a better way of selecting what to
> publish, so we can have internal files with Dartdoc comments.

You can use DartDoc all you want in the implementation files. However, the
comments that I changed to '//' were not DartDoc comments in the first place.
They were just more verbose than they had to be. :)