Fall 2019 pre-release

Tagging a version before attempting integration of style update, to make for easier comparisons if I need to fix things

IT Pro Forum June 2019 edition, introducing tags, branches, and undoing things

The standard SWC lesson doesn't address undoing things, so I added a segment on tagging, branching, and the various ways to undo things.

IT Pro Forum, summer 2018 edition

Customized for use in a 2 hour time window in a computer lab with Git on Linux already available to students.