Problem: yi' don't highlight last character since
8ce504820a.
Solution: Always use `opts.inclusive=true`, since calculation of `"]`
(`b_op_end`) have taken `inclusive` into account.
Problem:
`vim.validate()` takes two forms when it only needs one.
Solution:
- Teach the fast form all the features of the spec form.
- Deprecate the spec form.
- General optimizations for both forms.
- Add a `message` argument which can be used alongside or in place
of the `optional` argument.
Problem:
- `vim.highlight` module does not follow `:help dev-name-common`, which
documents the name for "highlight" as "hl".
- Shorter names are usually preferred.
Solution:
Rename `vim.highlight` to `vim.hl`.
This is not a breaking change until 2.0 (or maybe never).
