Branch structure

Now that we have a single merged document we care about, I've moved it to
the gh-pages branch so it's accessible from
http://w3c.github.io/touch-events/touchevents.html.

I've updated the README.md
<https://github.com/w3c/touch-events/blob/gh-pages/README.md> there to
describe the new branch structure.  Someone with the power should make
gh-pages the default branch and delete 'master'
<https://github.com/w3c/touch-events/issues/15>.

Look good?

Rick