Olympic live streams fix

[fs ck]

I've just committed a change to git that allows the Olympic live
streams to work. They use a new /mediaselector/5/ URL so now this is
detected.

You should be able to use: get_iplayer --url
"http://www.bbc.co.uk/sport/olympics/2012/live-video/<pid>" --get
or: get_iplayer --pid <pid>

Many of these links are in:

http://www.bbc.co.uk/sport/olympics/2012/live-video

Sometimes you'll find that the <pid> is a channel id such as
'http://www.bbc.co.uk/sport/olympics/2012/live-video/bbc_one_2012_hd'
and in this case you'll need to use:

get_iplayer --pid bbc_one_2012_hd

Unfortunately for some unknown reason I'm still having trouble getting
pid 'bbc_three_2012_hd' working.

Have fun.