Add more options to settings GUI including game-speed slider

This adds several new hidden settings to the Red Alert and Dune 2000 settings menu including the anticipated game-speed slider from #2058.

![game-speed-slider](https://f.cloud.github.com/assets/756669/158193/daa61f4a-76dd-11e2-92bf-efb69cda9330.png)

![cap-fps](https://f.cloud.github.com/assets/756669/158195/de367b14-76dd-11e2-99e7-1576f82df149.png)

![new-sound-options](https://f.cloud.github.com/assets/756669/158197/e543b340-76dd-11e2-967b-7e9ca0e871e2.png)

![debug](https://f.cloud.github.com/assets/756669/158198/e955c518-76dd-11e2-8e72-cf06b1ba07c8.png)