LÖVE 11 fixes

[qixils]

• [x] Check for remaining conversions from isDirectory and fix them
• [x] Disable letterboxing by default
• [x] Fix Android scaling issue
• [x] Fix color-sensitive slope tileset issues
• [x] Fix color-sensitive debris tileset issues
• [x] Update game icon to use modern mario palette
• [x] Fix Luigi hat colors?? CNR
• [x] Unchangeable character colors still?? CNR
• [x] Also loading with incorrect colors. Affects highly custom characters like Kirby.
• [x] Text color copying wrong colors
• [x] pairs issues
• [ ] Audio quality regression? https://github.com/love2d/love/issues/2091
• [x] Dialog text defaults to black instead of white

  After looking at the code in dialogbox.lua (and testing the code snippet to make sure), it re-normalizes the default white color, which is already manually normalized

Closes #595 Closes #611 Closes #612 Closes #617 Closes #618 Closes #619 Closes #621 Closes #622 Probably closes #606

[qixils]

Not updating to 11.5 atm due to https://github.com/love2d/love-android/issues/258 as well as likely slow updates to makelove