[PATCH 0 of 6 V2] Second version of peer queue

[Sune Foldager]

Changes from first version:
- Sent as --git
- Split first patch into two: One introduces the methods and changes all the
  call sites, while the other one introduces the peer classes and renames the
  necessary files.

I didn't change the last patch (documentation) as Greg suggested; I am not
necessarily against it, but I like the current overview, which also makes it
easy to see the difference between the modern and old API. Thoughts?

That one doesn't have to be pushed right now/soon anyway.

-Sune