add video and audio formats

[Modernizr]

Per Faruk:
"We should support everything that at least 1 browser has implemented and is a common enough format that people would use it"

for video:

• ogg, h264

for audio:

• ogg, mp3, wav, .m4a

I'm expecting we'll implement with a Boolean constructor so it'll be, essentially, as follows:

Modernizr.video = new Boolean(true);
Modernizr.video.ogg = true;

Modernizr.video        // true
Modernizr.video.ogg // true

[paulirish]

media type support for audio/video. rejigger for opera compat. closed by ae7a275