Add distributed cloud diagram

Add both the Dia source (uncompressed) and the exported SVG.

SVG is exported using the "Scalable Vector Graphics" export option, as
opposed to "Cairo Scalable Vector Graphics", "SVG compressed" or "SVG
plain".
Add graphic for CAP theorem

Missing from 560eea6c5a464be850bd5279a0ee9c8bb56ec3d2.

Image credit: Benjamin Erb, from "Concurrent Programming for Scalable
Web Architectures"
(http://berb.github.io/diploma-thesis/community/061_challenge.html),
CC-BY-SA 3.0
Add distributed cloud diagram

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