Improve API review process

Notes

- API vs header review? Our header review has become an API review – or even an implementation review! - API design used to be: Go talk with Jasmine; but that doesn't scale. Do we need a group of reviewers? - How can we get people involved with API design earlier?

 + tooling might help – Daniel has a  bot for flagging changes
 + add checks for common mistakes (boolean trap, naming of getters)
 + but tooling won't solve a social issue