Algol-like indenting doesn't work for Lisp as we tend to open (and
close) many forms on one line. This generally puts the cursor
where it should be, though it is probably confused by strings
with brackets and things.
That means we can now have highlighters active at global, buffer, and
window scope. The add-highlighter and remove-highlighter syntax changed
to take the parent path (scope/group/...) as a mandatory argument,
superseeding the previous -group switch.
The option is now used as a fallback when detection by extension fails. Some
scripts like `base/mail.kak` and `base/html.kak` still rely heavily on it.
