MKVToolNix 89.0 “And the Melody Still Lingers On (Night in Tunisia)”

# Version 89.0 "And the Melody Still Lingers On (Night in Tunisia)" 2024-12-27

## New features and enhancements

* mkvmerge: AC-3 writer: mkvmerge will now use the codec ID `A_AC3` even for
  streams with bitstream IDs 9 or 10 instead of the deprecated codec IDs
  `A_AC3/BSID9` & `A_AC3/BSID10`. Fixes #2387.
* MKVToolNix GUI: multiplexer: the mechanism for setting track languages to
  specific values upon adding a file has gotten a new option to always set the
  language, no matter whether or not the source container provided a track
  language or what it was set to.
* all command-line tools: implemented an escape mechanism for when you want to
  use the `@` sign as the first character in an argument to an option such as
  `--title`. To escape it the `@` sign has to be doubled as in `--title
  @@midnight`. Implements #3768.

## Bug fixes

* mkvmerge, mkvpropedit, MKVToolNix GUI's multiplexer & header editor: the
  MIME type for TrueType & OpenType fonts will be set properly to either the
  current MIME types `font/ttf` & `font/otf` or to the legacy MIME types
  `application/x-truetype-font` & `application/vnd.ms-opentype` depending on
  whether the "use legacy font MIME types" option is disabled or enabled, even
  if the MIME database used by Qt returns the wrong one or even other MIME
  types such as `application/x-font-ttf` & `application/x-font-otf`. This was
  the case on Windows due to Qt 6.7.3 switching to a different embedded MIME
  database. Partially fixes #3751.
* MKVToolNix GUI's multiplexer & header editor: ensured that both the legacy &
  the current font MIME types are always present in the MIME type combo boxes
  of attachments, no matter what Qt's MIME type database contains. Partially
  fixes #3751.
* MKVToolNix GUI: the "disable tooltips" option in the preference will now
  disable the tooltip for the status bar, too.