Release v0.17.0

• add Gentoo::Portage::Q module and migrate to it for get env vars, get repos, etc
  so should fix Gentoo bug #581490 and github #26

• introduce App::gcpan and start slowly moving code from g-cpan to there

• rework Makefile.PL a little

  • keep non-core & core deps separatly
  • place test reqs under proper section

• migrate to 'Changes' (CPAN-like) instead of 'ChangeLog'
  but keep 'ChangeLog' anyway to save history

Release v0.16.9

Gentoo bugs #573308, #583374

Release v0.16.7

A lot of fixes, including bugs #432992, #431080, #578678