Halloween Theme + Dark Pixel Levels

Additions:
- Added the new Halloween themed panorama to the start menu! I really like the images they took, it is a really nice scene to look at.
- Added a few textures with gray borders, and adjusted their borders to be solid black instead. Now they will contrast more with the backgrounds behind them.

Changes:
- Updated the start menu title texture to match the most recent version in the game. I'm not quite sure if I like the new logo as much to be honest, but I will add support for it in the meantime to see if that changes.
- Reverted the inventory Empty Armor Slot textures back to their completely vanilla appearance, because I don't think my custom versions looked vanilla enough.

Fixes:
- Adjusted many extra-dark textures to be at most rgb(18,18,18) or rgb(0,0,0) dark only. After learning a lot about UI colors with my work in web development, I found that a lot of my old textures are darker than the recommended base colors for interface elements, so I will be retexturing any textures that are darker than they should be, in regards to contrast issues. More of these will come as I stumble across more, as there are so many to do! It will be easy though, just gotta keep workin' at it.

Removals:
- Removed the hide Debug content feature, as it was causing Debug GUI errors to pop up on the screen, and it isn't necessarily a dark theme related feature anyways. There are still other packs out their to accomplish that too, so it shouldn't be a problem.
- Removed the outdated Accessibility tab icons, as they were there to fix a texture inconsistency that isn't present anymore.