OpenCS settings

EDIT3: This set of changes include two different implementations for user settings and they do not mix very well together.  It would be best for someone else to start again and perhaps extend the current implementation for more presentation options.
Predefined window sizes aren't what's bothering me. It's that they are pulled from Ogre, which is complicated (thanks to the terrible interface) - adding a stupendous amount of code for something so simple.
It's not worth it to maintain this code, because there is literally no value in using Ogre's supported fullscreen resolutions compared to shipping with a "predefined" resolution list.