Custom palettes

[pierce-smith1]

[!Caution] @McAwesome123 Because of the way I decided to resolve merge conflicts, this might explode or do weird shit when you try to run it locally. I accidentally repurposed the index of one of the trail config options for a new one I added in this PR. I would recommend you just delete your entire yokscr registry key before trying to run this.

27 and part of #28.

You can now create your own palettes!

This PR adds a config option, "Use custom palette set," that replaces the normal palettes with ones you define. It also adds a GUI tool for designing your own palettes which will be used if you choose that option.

All custom palettes are stored directly in the registry. As you create palettes, you will make _CustomPalette: entries that store a semicolon-separated list of colors. A comma-separated list of all custom palette names is stored in _CustomPalette_index.

This is a pretty big PR, but unlike my last ones it's mostly new code and not just refactoring, so it might actually be worth it to read.

Some concerns:

• I have tried to protect against putting nasty characters and other bad stuff in the registry via the palette names, but I may not have fully locked that down. More rigorous testing might be needed.
• Some of the UI controls do some kind of janky shit and I'm surprised it works at all on my machine. I can't wait to find out it doesn't work on other computers.
• Are there performance issues?????

[pierce-smith1]

I have really bad habits, never name your commits like this.

[McAwesome123]

I have really bad habits, never name your commits like this.

[pierce-smith1]

I'm afraid of this but it's going out.