abs isn't declared

[yurivict]

On FreeBSD:

src/video/videomode.cpp:66:12: error: use of undeclared identifier 'abs'
    return abs(this->width-other.width) + abs(this->height-other.height);

I have to patch it, add #include <stdlib.h>.

[sudden6]

Could you open a PR with that fix?

[antis81]

@yurivict You can actually use qAbs() which doesn't require such patches. :)