Rant / guideline

[Stephen Baker]

I'm about 4-5 hours into sorting through a pull request and I have
something I want to get off my chest; maybe this should go in
contributing.txt

1. Do not refactor existing code in the same pull request that you add a
feature.
2. If you insist on breaking rule #1 (e.g. because it makes your feature
much cleaner) then do all refactoring at the beginning of your pull
request (independent of and before your feature commits).

[Edvin Linge]

Sounds good to me.

/Edvin