FIX for issue 446. 'each' for Strings undefined in ruby 1.9

Changed from 'each' to 'each_line' because ruby 1.9.x no longer has 'each' for Strings.

'each' for Strings was removed in ruby 1.9 because it was confusing what you wanted to iterate over (chars, lines, etc).

'each' and 'each line' have the same functionality but 'each_line' is still available in 1.9.X.