It's pretty much a simplified copy of the Linux script, lacking fancy colors.
Also, I had to drop Python testing, because it's not easy to pass the Python
module location to the script, and I have no pressing need to run the Python
tests at the moment.

The two functions featuring nNull are not particularly needed, so
I simply removed them.

They don't actually do anything. And even if they did, all components are
enabled by default, anyway.

FFmpeg now requires that frames allocated with avcodec_alloc_frame are
freed with avcodec_free_frame.

The HAVE_DOC_GENERATOR variable was always true.

Absolute destinations are not necessary, and prevent CPack from working.

use `bash` shell instead of `sh`, since on Ubuntu `sh` by default is `dash`,
and `dash` doesn't support `PIPESTATUS` feature used in this sctipt

Thanks to SpecLad.

Thanks to SpecLad.

Modified resetCvImage() in cap_ximea.cpp, so that the IplImage* frame is also updated after the resolution has changed via set(CV_CAP_PROP_FRAME_WIDTH, value)/set(CV_CAP_PROP_XI_DOWNSAMPLING, value)