Start seamcarving video filter. I'm commiting this mainly to get it in a windows build. This still needs some heavy optimisation, support for vertical resizing, colors and upscaling.

Sample command line for those who want to test: time ./vlc fake: --fake-file ~/images/NATURE-Fakarava_400x300.jpg --fake-fps 5 -I dummy --control rc -V x11 --video-filter seamcarving@s
You can change the croping by using commands like:
@s crop 200 (a crop value of 0 resets it to the default mode)