Save video replay of the match

I've started to implement #114, I'd like to have your opinion @trigun0x2 and @gtch on this build.

Before merging this, you need to take into account that this adds an extra dependency to xuggle (to compress the video) which makes the final Hearthstats.exe around 70 MB ... instead of the current 14 MB.

It would be great to have an option in the updater to only download dependencies once !