Added image output to manager, added plots to results pages

Can generate images from manager program with the -I option
Can generate a video from these images with the -v option (Note: just runs ffmpeg)
These two options only work if the program was built with graphics enabled.

Note: You can generate a video from a saved log file by "./stratego -v video -o logfile"
So that's cool.

Results pages look nicer. Fixed bug with score updating between rounds.
Added pretty plots. Most plots end up being straight lines. But its pretty anyway.