Validation fails on short gaps between complex subs

[cconcolato]

Netflix timing guidelines for subtitles recommends to "close the gap" between subtitles when the gap is smaller than 500ms by setting the gap to 2 frames.

This means that the validation fails on perfectly acceptable documents that produce an ISD sequence with short, empty ISD documents in between long-duration, non-empty ISD documents. The software (and maybe the spec) should be updated to work with such documents.