cif_linguist should affirmatively ensure that output whitespace is not too long

[jcbollinger]

Under some circumstances involving input CIFs with long (but not necessarily over-length) lines, and especially with long runs of whitespace relative to the line-length limit, it is possible for cif_linguist to emit CIF that contains lines longer than the limit. The known mechanism by which this could happen will yield only whitespace (possibly including a comment or portion thereof) in the over-length tail of any such line.

Typical CIFs are not at risk of triggering this issue, so its severity is downgraded.