Mwti's Stone Expansion 2.2.0

Split Stone and Smooth Stone into two materials!
- Smooth Stone (vanilla minecraft block) is now its own material with variants! (now called Smoothstone),
- Light textured variants for Stone have been replaced with a darker, stone-like textures
Updated textures:
- Changed Purpur Bricks design,
- Changed Chiseled Diorite design,
- Changed Brick Pillar Top and Chiseled Bricks textures,
- Other minor tweaks to numerous blocks