Merge pull request lightbend#31 from lightbend/deanw-more-final-refin…

…ements

A few more final(?) refinements

Added basic error handling idioms and exercises to improve them.

Merge pull request lightbend#29 from lightbend/deanw-rework-full-day

Refinements to prepare for the full-day sessions at YOW!

Fixed a few missing things in the slides.

Merge pull request lightbend#28 from lightbend/protobuf-upgrade

Updated the protobuf dependencies, which should fix issues on Windows.

forgot to create the non-notes PDF

Minor tweaks to the text

Version consistency

Minor text change

Merge pull request lightbend#24 from lightbend/strata-london-refinements

Strata London refinements - WIP