Same Document References for digital signatures

Proposal from Dennis Hamilton in OFFICE-2656: Add a statement to ODF 1.2 Part 3 cd1-rev02 section 2.7 immediately after the definition of file entry base IRI (third bulet) as follows:

• An IRI whose URI matches the rule for "relative-ref" defined in section 4.2 of [RFC3986} with a "relative-part" matching the "path-empty" pattern, with no query part, and only a fragment part shall always be resolved in the file having the URI, as if it were an IDREF to an element having an ID attribute having the fragment part (without the "#") as its value. The following procedure does not apply. The choice of Base URI is irrelevant.

Amend third bullet in section 2.7 as follows:
Relative IRI references shall be resolved as defined in §5.2 of [RFC3986] using the file entry base IRI as base URI. *Relative IRI references that match the rule for "relative-ref" defined in §4.2 of [RFC3986] and whose "relative-part" component matches the "path-empty" production shall be resolved as a "Same-Document" reference defined in §4.4 of [RFC3986]