R57.A1

This interim release is mainly intended for the upcoming @AmusementClub VS portable.

Compared to R57.A0, we have Incorporated these changes:

1. restored VideoFrame.planes Python API
2. restored vspipe option -c / --preserve-cwd (while keeping -c y4m support intact)
3. record function names along with namespace in graph introspection API (getNodeCreationFunctionName), and modified vspipe so that vspipe --filter-time would differentiate between std.Expr and akarin.Expr.
4. incorporated upstream fix for vapoursynth#833

core plugins:

• imwri: https://github.com/AmusementClub/vs-imwri/releases/tag/vA.R2
• subtext: https://github.com/Masaiki/subtext/actions

Note:
Updated new release release-x64.new.zip and release-x86.new.zip that includes bundled coreplugins. The previous released files (release-x86.zip and release-x64.zip) do not include coreplugins and VSScriptPython38.dll due to unexpected build failures.