Feature Release 07

The big change in this release:

• Add a "default script" option for opening audio or video using VapourSynth. When opening a file not ending in .py or .vpy using the VapourSynth provider, the filename will be passed to this default script to be opened as a media file (or in any other way - it's freely configurable after all). This option defaults to using LWLibavSource for video and BestAudioSource for audio - these need to be installed.

  Note, however, that the VapourSynth video provider continues to assume CFR. To properly load VFR video, you'll need to manually create and load a timecodes file.

The rest are a bunch of bugfixes that accumulated over the last month:

• Fix a colorspace conversion bug for BestVideoSource.
• Fix a bug where shift+selecting subtitle lines would make the selection jump to different lines in files containing folds.
• Fix redundant errors such as "Avisynth not found" or "Vapoursynth not found" when trying to open video or audio from an invalid file name
• Fix a crash when cancelling automation script on debug builds like some Linux builds.
• Fix Avisynth not being bundled in the portable Windows releases.
• Add missing string resources to the Windows executable. This will make menus like the "Open With" menu in the file explorer show Aegisub with its proper name, instead of just "aegisub.exe".
• Bump VCRedist to version 17 to match the VS version used in the Windows CI builds.
• Work around the second sandbox violation bug so that the project can again be built with the latest meson version.