Issue Title: Fullscreen stretching
Description: When you fullscreen on a wide screen monitor, things stretch pretty bad. If you've got a huge wide screen monitor, it looks horrible.
Suggestion: Since the fullscreen is handled by something other than the scripts, it'd be nice if you set up a way that it'd englarge it while keeping the proper aspect ration (and just showed black at the sides if the screen is too wide).
Though I think this crosses the line into a new game client, rather than something to do with the editor. However, if you DID make a new game.exe, it'd give you a lot more freedom. Including the ability to make RMXP games multiplatform. (not to mention, being able to name it something other than game.exe and still run encrypted files) I totally understand if this request goes outside your scope, but it'd be cool if you were able to keep the fullscreen aspect ratio the same.