- Add Appveyor badge
- Add Appveyor.yml definition, with encrypted ATOM_ACCESS_TOKEN
- Add cibuild.cmd script to launch cibuild on Windows
- Prepare to release Atom on Windows from Appveyor (but don't do it yet)
- Reduce dependence on JANKY in ci scripts + tasks
- Suppress release activities on PRs for Travis and Appveyor
- Cache ~/.atom/.apm, ~/.atom/.node-gyp/.atom, and ~/.atom/.npm on Appveyor
