[osis-core] 1.9.4 - role on <language>

[Chris Little]

I _think_ this was a typo, but we have a "role" attribute on <language> 
(type xs:string).  I think this was intended for what is currently the 
"use" attribute.  FWIW, I prefer "use" since it distinguishes the 
attribute from "role" that appears on those other elements in <header> 
and discourages the mistake of using the same attributes on the language 
element.

Correct me if I'm wrong.

--Chris