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.
``` Remove outdated unlinked-by-default packages ```
``` Remove outdated default-unlinked packages ```

Probably the former. ``` default-unlinked ``` isn't much shorter than ``` unlinked-by-default ``` and the latter is a slightly more clear explanation.