* try new images, make sure that ffmpeg is built as LGPL library

* prepend ~/bin to PATH

* enable linux video test

* add ffmpeg pkg config location

* cherry-pick FFmpeg fix from OpenCV upstream

* add FFmpeg lib path to linker flags

* add also libjepg-turbo

* add additional flags

* add missing $

* update READMEs

* enable all video tests

* Build LGPL FFmpeg shared libraries.

OpenCV should automatically use them.

* Also disable the x264 encoder.

* Also disable xvid

* Confirm FFmpeg is being built correctly.

* Make log easier to read.

* Travis-CI Mac environment only has 2 cores.

* PATH editing only needed in Windows

* DLL load works without in Windows, too

automatically on macOS