Mostly comments but some derived names too.

Change-Id: I1e01dccca98de6688e1426c7a9309f6fd6a1e368
Reviewed-on: https://go-review.googlesource.com/27415
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>