[RDFa] Issues List Pointer moved

As per one of my actions, I've updated the old RDFa Issues Page:

http://www.w3.org/2001/sw/BestPractices/HTML/2005-current-issues

to point to the tracker:

http://www.w3.org/2006/07/SWD/track/

Michael: when you're done transferring the issues, go ahead and clear
the RDFa issues wiki page we'd started and never fully finished, and
update any wiki links you can find. I don't want to delete anything
until I know you're done!

-Ben