reogranizing for more SDOs

--HG--
rename : Makefile => ietf/Makefile
rename : draft-miller-xmpp-e2e.txt => ietf/draft-miller-xmpp-e2e.txt
rename : draft-miller-xmpp-e2e.xml => ietf/draft-miller-xmpp-e2e.xml
including XSF-related works