The version output by `script/version` should indicate if there are any uncommitted changes or any unignored untracked files

The version output by `script/version` should indicate if there are any uncommitted changes or any unignored untracked files.

Indicate this by appending a `+` to the version name.

Use the following zsh to achieve it:

```shell
"${"$(git diff-index HEAD --;git ls-files --exclude-standard --others)":++}"
```
