additional example

Hi,

following some discussions in the RDF-TF, we thought it would be good to 
include some explaination about
- representation of captions/signing in the RDF ontology
- how to deal with multiple languages

I therefore propose to include those two subsections to
 
http://dev.w3.org/2008/video/mediaann/mediaont-1.0/mediaont-1.0.html#examples
(currently section 6, which I proposed in another mail to swap with 
section 7)

  regards

   pa