Initialize global network and example PIL/Pillow support.

Administrator
2023-03-20T18:20:38Z

*Created by: billyshambrook*

This is recommended, since it avoids the overhead of implicitly doing
the setup for each session.

This avoids the following warning message when the input is over HTTP:

Using network protocols without global network initialization. Please use avformat_network_init(), this will become mandatory later.

And cleaning up the example scripts to work with either PIL or Pillow.