Proposed note about C064 and C065

Note to be added after C064 and C065 in Charmod Fundamentals:

NOTE : C064 and C065 are meant to avoid specifications referring to 
obsolete and potentially unavailable versions of the standards.  It 
should *not* be construed as an obligation to track the very latest 
update version of Unicode, especially when a specification has no need 
for this level of details and all is that is desired is a generic 
reference.  Specification editors may consult 
http://www.unicode.org/versions/latest for the latest version of Unicode 
and search the ISO Catalogue from http://www.iso.ch/ for the latest 
version and published amendments of ISO/IEC 10646.