Vim (Vi IMproved) version 8.0

This the first major Vim release in ten years. There are interesting
new features, many small improvements and lots of bug fixes.

Among the new features are:
- Asynchronous I/O support, channels, JSON
- Jobs
- Timers
- Partials, Lambdas and Closures
- Packages
- New style testing
- Viminfo merged by timestamp
- GTK+ 3 support
- MS-Windows DirectX support