TODO for portage-2.2 release:
=============================
x package set integration in emerge (genone)
x user interface for preserve-libs FEATURE (genone, fuzzyray?)
x resolve the eselect-news situation (genone)
- package set documentation (genone)
- repository configuration file and `emerge --sync [repo_set]... [repo]...`
  support for overlays and binhosts (zmedico)

(-  denotes open/incomplete tasks, x denotes completed tasks)