Import the extension, index.html and app.js files

As discussed here github.com/GoogleChrome/webrtc/pull/85 with @juberti.

These are only the essential files from my example app.

In order to run the example, one needs to serve it over https.  For
convenience I included a small ruby script in the [original
repo](https://github.com/wpp/ScreenStream) but I'm not sure how you feel
about that.

What is also missing is the README any thoughts on that? Should the
documentation only live in the `.js` files? (I would need to add some
then.)
Updates manifest urls for github pages (@jiayliu feedback)
adding maxplaybackrate as a codec parameter
making names shorter
Merge pull request #103 from minyuel/master

adding maxplaybackrate as a codec parameter
Merge pull request #86 from wpp/desktopCaptureAPI

Add desktopCaptureAPI example (for screen streaming with an extension)
Merge pull request #105 from GoogleChrome/testrtc

For reals - initial version of TestRTC.
Merge pull request #109 from GoogleChrome/testrtc

Add UDP/TCP connectivity tests.
Merge branch 'master' into testrtc3