[Feature Request] Add support for BestSource

[Dan64]

Ps.: Yes, stuff like interlaced or mixed vfr content is simply 'evil' and in my mind a production mistake

I do agree with you, but unfortunately, it could happen the need to encode damaged videos or videos with audio sync problems once they are encoded, especially in the case Hybrid is used for Video Restoration of old movies. In this case I'm using Handbrake to produced a h264 CFR video with low compression and then I use Hybrid for Video Restoration.

[Selur]

btw. bestsource "is still in the extremely experimental phase"
see: https://github.com/vapoursynth/bestsource/issues/25

Cu Selur

[Dan64]

It seems that the substitution of FFMS2 with BestSource is that the latter: it is at least correct unlike FFMS2. 
The good news it that: FFMS2 should improve the correct way soon.
For the moment I will continue to use as default source reader LSmashSource.