Move advanced mode toggle to the options panel and add granular control

[Zweibach]

As of right now advanced mode is a toggle under the help menu and turning it on does stuff. What stuff? I'm not entirely sure to be honest, closest thing to a list there is of it is to search the source code for any time the flag is checked for. But I think being able to set files as alternates is one for whatever odd reason.

My suggestion is to have an "advanced" tab in the options panel with a toggle for each individual feature or limiter. Each toggle should also come with a warning about the sort of fuckups you can expect to get if you do dumb things with it on. This puts the advanced mode in a more sensible place (why are so many things under the help menu in the first place?) and lets users turn on the specific advanced features they want and actually in some manner informs the user that the feature even exists in the first place.