[web2py] suggested fix for http://web2py.com/semantic

[Nico de Groot]

Massimo,

The embedded youtube video link on above page is no longer valid (user
pulled the video off), alternative: http://www.youtube.com/watch?v=HeUrEh-nqtU
or - longer -  http://www.youtube.com/watch?v=OM6XIICm_qo (TED talk)

Nico de Groot