Properly re-indent comments.

[jordwalke]

One issue that's going to come up when converting code from OCaml, and also when indenting your own code (but less likely), is that comments now begin in a new column, and therefore must be shifted over.

Right now, we just copy the entire comment including newlines, but shift the starting column over. See the screenshot for how that will lead to improperly indented comments.

We should indent the entire comment over by the same amount that we are shifting the first line.

Here's an example of the formatter running on an existing comment.

[jordwalke]

@cristianoc - I noticed that this happens occasionally when converting a big project from ML - and I am tackling this right now. It will make the results much more beautiful.