Quicksave/quickload functionality

[hvacengi]

While quicksave/quickload has not been documented or supported for a while, the bound variables still exist. I would like to remove the existing broken logic and replace it with something that works, if possible. I'd also like to move the logic out of BindingsUniverse and into KUniverseValue. Ironically, if quickload worked properly now, we would be executing a quickload any time debugdump() was called (since quickload is a bound variable where "getting" the variable executes the quickload).

I think I have this solved, and I'll submit a PR later with the info. For the time being, I don't plan on supporting arbitrarily named saving or loading (like loadgame("checkpoint1")). This is mostly due to complications in figuring out valid names for save files, and getting that information accessible by the script.