This repository is hosted on opendev.org's
gitea server, and doesn't get mirrored to
github currently (we may add mirroring in
the future). We can swap a bunch of URLs
that assume the content is on github and
older infra cgit servers with correct URLs.
Meetings have moved from IRC to MeetPad,
fix the corresponding details in the README.
Also use this commit to strip trailing
whitespaces across the repository.