- If the second address is empty, it is assumed to be `.`
- Regex addresses and `:substitute` now integrate with search history and
respect case sensitivity settings
- Patterns for `:substitute` can't be delimited by
- `:set` now supports inverting options using `:set inv{option}` and
`:set {option}!`
- New commands: `:new`, `:vnew`, `:exit`, `:xall`, `:wall`, `:qall`, `:update`
