Don't use keg-only and pouring jargon.

This is unnecessarily confusing to end-users and the "fun" naming doesn't really communicate anything. @mistydemeo and I talked about this.

CC @adamv @mistydemeo @jacknagel @tdsmith @asparagui for thoughts and review.
'Tis a fair point. The mechanism itself is complex, the jargon more reflects that rather than being clunky for the sake of being clunky. It's a difficult thing to balance, I guess. Anyway, I defer to you maintainers :wink: