Add Pixel Scaling & Allow Setting UPS

[nixpulvis]

This fixes two main issues I had with this implementation of Conway's Game of Life and makes a few other small changes. Mainly:

1. The scaling feature was blurry, so I've removed it, and implemented a simple set of for loops to draw extra pixels instead. This means that SCALE is now a u32.
2. I've added an explicit EventSettings to allow setting the UPS, aka updates per second. This makes high scale games much more fun to watch.
3. I've also made it default to fullscreen. I'm happy to undo this, but I feel it really highlights how awesome this game is.

I've had to downgrade the version of image to still render at 1920x1080 correctly. When I get some more time I can look into what's changes with the latest versions.

P.S. Playing this game at 1920x1080 is very very fun, thanks for making this.

[crazymykl]

These downgrades are pretty severe.

[nixpulvis]

Yea, I need to spend a few minutes looking into why things render at the wrong scale with the latest versions. As things are with this PR (at least on my setups) at SCALE = 1 each cell is exactly one pixel. Which is what I want.

[nixpulvis]

Actually it seems it's just my laptop screen that's blurry with the latest versions. I wouldn't be at all surprised if this is a bug (or some half worked feature) in piston, or glutin.

[nixpulvis]

Just pushed with a patch to the underlying window in 1e6bf29. I'm not 100% sure why there's a draw_size and size to be perfectly honest, so I'll need to dig more into this still.

[crazymykl]

Fixed by #7.