Add distributed cloud diagram

Also, move the slides starting with "So:" (including the diagram) into
their separate vertical section.
Reduce size of CAP graphic

Make sure the caption fits for proper CC-BY-SA credit.
Open external link in new window
Add section on Glance replication

Dia and SVG export settings as in
7ab23082adab681de3ff147e37c12af9025e7649.
Add notes on Cinder

Point out that while Volume Mirroring is a good step in the right
direction, but for Icehouse will only manage backend-specific
replication *within* a single Cinder instance.
Add notes on Nova and Neutron

Point out that there isn't much of a distributed cloud story for
either, yet. However, multi-cloud Heat helps us get a lot closer to
where we want to be, eventually.
Split sections into present state and possible post-Havana state
Add two summary slides
Add facility to auto-generate QR codes, client-side, with JavaScript

Provided by qrcode.js (http://davidshimjs.github.io/qrcodejs/) by Shim
Sangmin, MIT license.

* Update Makefile to symlink qrcode.js from ../qrcodejs.
* Add a CSS class to display the QR codes at a decent size.
* Add a function to index.html for easy QR code creation.
* Update README.md
Add QR codes for links to GitHub and hastexo.com
Add Twitter and Google+ links