[1.0.22] Add grayscale heightmap and fix graphics, chests and structure seed mode
New :
- Add heightmap grayscale map (toggle in Settings > Show Heightmap)
- Add menu to optimize grayscale map (which is very slow) by only running it every 1,2,4,8 or 16 blocks (go in About > Optimize heightmap)
Fixes :
- Multiple chest were not updated in the UI when using the mouse
- Icons were optimized to not overflow
- Move everything of Stdout/Stderr to logging