Two broken links fixed.

Line: 152 http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html
Status: 404 Not Found
The link is broken. Double-check that you have not made any typo, or mistake in copy-pasting. If the link points to a resource that no longer exists, you may want to remove or fix the link.

Broken fragments:
http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#audio (line 152)
http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#video (line 152)
- Broken Links @ Chapter 5: VIDEO ON THE WEB #55
Merge pull request #53 from estebanav/master

Broken Links @ Chapter 1: HOW DID WE GET HERE?