Move it from libvlc where it didn't work to vlc binary where it really
should be

Now VLC can be started from dock again after [13d838b6]

Previously, we'd assume we have the source address, which was confusing.

It is computationally more expensive than the ugly one (and has higher
priority). Yet, in my opinion, it sounds even worse.

The ugly resampler is almost as fast yet way better.

For both vaapi and dxva2, not enough testing has been done.

It is not yet activated (the build system part is missing).

This avoids "*-caching variable does not exist" errors

Now, we get the URL directly. This is much simpler and much less
confusing. Also a few missing network protocols.

Improves seeking experience by sending less seek requests and actually allowing output to update between them.

indent comments screwed by copy-pasting

This patch needs more testing, I think.

Some instruction sets can't divide (e.g. ARM), but pretty much all of
them can shift bits.