Adds a new Arcade Machine.

Adds "The Orion Trail" to the game as an Arcade machine. Very loosely based on the Oregon Trail, it's a series of random events and weighted choices along a static path.

Every game the series of events, and the success or failure of different choices will vary.

I'm sure it's not perfectly balanced, but it works decently well.

![orionmontage](https://f.cloud.github.com/assets/2319040/1670269/42889f18-5c91-11e3-965e-bde73e7e6ea3.png)
![orion5](https://f.cloud.github.com/assets/2319040/1670467/c9398148-5c97-11e3-9742-4d07634057f0.png)