Discard auth=no attribute

[proycon]

The non-authoritativeness of certain FoLiA elements, like alternatives, originals in corrections, suggestions for correction, was expressed using the using auth="no" attribute. This would facilitate the job of parsers but it introduces too much complexity. I want to remove this attribute from FoLiA v2.0 and keep the notion of authoritativeness as an internal library thing only (certain elements being by definition non-authoritative, and therefore all elements in its scope too).

[kosloot]

Fine with me. Didn't see a real use case all these years