AWS::S3::S3Object#read now returns the extra response in block mode.

You can now get the object contents AND the object metadata in a single
call to S3Object#read.

    obj = s3.buckets['foo'].objects['bar']

    resp = obj.read do |chunk|
      # write the data somewhere
      file.write(chunk)
    end

    resp[:etag] #=> '...'
    resp[:meta] #=> a hash of object metadata