erratum: terminology about IRIs is (slightly) wrong in RDF specs

Hi all,

RDF specifications talk a lot about IRIs. Sometimes, the distinction is 
made between absolute IRIs and relative IRIs. I discovered some time ago 
that this is inaccurate.

According RFC3987 [1], IRIs can not be relative, only *IRI references* 
can. Therefore, "absolute IRI" is redundant (but correct), while 
"relative IRI" should be "relative IRI reference".

Note that, from what I saw, this impacts the following documents:

     RDF 1.1 Concepts and Abstract Syntax
     RDF 1.1 Turtle
     RDF 1.1 TriG – RDF Dataset Language
     RDF 1.1 XML Syntax

the others make use of "IRI", "absolute" and "relative" in a way that's 
consistent with RFC3987.

   pa

[1] https://www.ietf.org/rfc/rfc3987.txt