`x` is often criticized as hard to predict due to its slightly complex
behaviour of selecting next line if the current one is fully selected.
Change `x` to use the previous `<a-x>` behaviour, and change `<a-x>` to
trim to fully selected lines as `<a-X>` did.
Adapt existing indentation script to the new behaviour
This should cover all filetypes that already auto-insert comments,
except for rust.kak, which is left for a follow-up.
Most of these are straightforward, some explanation for special cases:
rc/filetype/zig.kak rc/filetype/cue.kak
These indent hooks used their own logic to indent after "{" only if
no comment was inserted. Replace this logic by checking if a comment
was inserted. This works because these "*-insert" hooks are run
before their respective "*-indent" hooks.
rc/filetype/php.kak
This also has some logic to insert "*" after "/*" lines. Basic
usage seems to work still. In future this should borrow from the
c-family one, which works a bit better.
If a line contains three slashes directly followed by a new line, the
next line is also erroneously highlighted as a doc comment currently.
Using a lookahead instead fixes this.
