Code/style cleanup

[dgw]

Main things:

• tabs to spaces to allow aligning line continuations better
• remove any commented out code
• restyle indentation & braces to use } else { (1TBS) style instead of Stroustrup

This is partly complete in my local copy, but I need to rebase it on top of current master and probably play with eslint.

[dgw]

Working on this is both good fun (learning about eslint rules) and incredibly frustrating (some rules do things that are just not quite what I'd like).

But I learned today that const doesn't mean "immutable"—a good thing to learn early in my ES6 journey. Seems plenty of ES6 developers think it does, but you can modify a const object's properties all you like. It's just not possible to rebind the name to something else in that scope, which is good. (Hey, I work on stuff like this to learn, so "fixing" this issue is working out exactly as intended.)