ACTION-63: Expanded HTTP examples

Hi,

I've added some examples using each part of the HTTP methods
(server-parsed fragments, time ranges and range-refer), along with
some brief explanations, at:

http://www.w3.org/2008/WebVideo/Fragments/wiki/HTTP_Examples

It's still fairly bare and I'd like to add more examples, especially
outlining what happens when the server doesn't understand a request,
or when the UA doesn't understand a response.

Please let me know anything that's particularly ambiguous,
non-obvious, or plain wrong, so it can be improved before this week's
telecon :-)

cheers,

Conrad.