* Fixing a small typo
* Fixed broken link to diagram. Fixed text references to incorrect node names in the diagram.
* Fix for issue #572
* Fix for issue #624
The history section gets us into the technical "weeds" way too fast for this stage of the book. We should be including it in a later chapter perhaps, or summarize it down to the essentials. For now, I've moved it all into contrib/history.asciidoc