Hack: remove deprecated files
hack/MAINTAINERS.md: a maintainer's manual.
Hack: update release checklist and reference it in REAMDE
Update maintainer's manual: every change should be done in a pull request.
Hack: update README
Hack: correct typo in release checklist
Merge pull request #1970 from dotcloud/cleanup-hack

Cleanup and reorganize docs and tooling for contributors and maintainers