Release process

When we release Navit, here are the steps we have to follow for now (April 2018):

• update the contributors list using: ci/generate_contributors.sh
• generate changelog using ~/.local/bin/gitchangelog
• cut tag (verify that master is up-to-date with trunk)
• attach artifacts from circleCI to the tag (don't forget the cab and the .exe for wince)
• On Sourceforge:
  • upload new version using: https://sourceforge.net/p/navit/admin/files/gh_integration
  • sourceforge news: https://sourceforge.net/p/navit/news/
• On Launchpad:
  • update: https://launchpad.net/navit/+announcements
  • verify that https://code.launchpad.net/navit is up-to-date
  • add the milestone and release on the trunk series: https://launchpad.net/navit/trunk
• publish a post to:
  • twitter: https://twitter.com/navitproject
  • facebook: https://www.facebook.com/NavitProject
• update the website download section and the blog: https://github.com/navit-gps/website/
• update https://en.wikipedia.org/wiki/Navit