Update to VideoIO.jl

* Use new BinDeps features like library groups

* Update build incantations for new versions/platforms

* Remove all postproc stuff

* update REQUIRES

This builds and loads on my mac, but the tests fail because it can't grab a certain file from archive.org.  This PR is a little cavalier in how it throws stuff out, so feel free to iterate with me here to get it to be what you want.
We aren't using these right now, so why don't we comment out both libavresample and libswresample.  I'm guessing that any audio resampling people want to do can probably be done in Julia.