Add scrollbars when needed (or configured)

[TheShihan]

I have a wordpress theme that has a rather narrow width for the content.

So now code gets some line breaks - which is okay, but what I would prefer is to show some (horizontal) scrollbar when the width is not enough to show the full code.

Would be great to have a global option to turn it off/on, which would also mean that people who do not like this can keep the old behaviour.