Kakoune v2020.08.04

• Introduce User hook support.

• The bold and italic faces are no longer built-in. Highlighters
  are expected to use face attributes (+b and +i, respectively) to
  decorate text.

• The lint-enable command no longer needs to be called to display
  linting errors. The lint-disable command was renamed into
  lint-hide-diagnostics.

• The +<length> part of a range-specs highlighter consistently
  refers to the length of the target range.

• clients stdin is transferred to the server, making it possible
  to pipe into kak -c <session>

• Faces can have an alpha channel, specified using the
  rgba:RRGGBBAA format.

• replace-ranges highlighter now support empty and multi-lines ranges

• %val{...} now expands to list of strings, $kak_quoted_... now work
  as expected with these.

• *SetOption hooks filter string will contain a value only for options
  of int/str/bool types to avoid performance issue with generating those
  on more complex option types.