Pull up following revision(s) (requested by is in ticket #1514):
share/man/man4/stf.4: revision 1.22
share/man/man4/stf.4: revision 1.23
Four and a half year after the end of 6bone, it should not surprise that the
web page dedicated to it is gone. Fortunately, 6bone itself is not referenced
in this manual page. Thanks to aniou@ircnet for the heads-up.
Add references RFC3068 and RFC3964; mark draft-itojun-... as expired.

(riz)