v0.7 Alpha 8: Filling in some gaps

Most of the "building blocks" tab is now completely retextured!

• Added Basalt, Polished Basalt, and Smooth Basalt
• Added the many, many colors of Stained Glass
• Added Blue Ice
• Added Packed Ice
• Redrew Deepslate
• Added Deepslate Tiles & variants
• Added Cracked Deepslate Bricks
• Added Dark Prismarine & variants
• Added Deepslate versions of coal, copper, and emerald ores
• Added End Stone
• Added End Stone Bricks & variants
• Added Infested Deepslate
• Touched up the infested block outline—it stands out from the inventory much more nicely now
• Added Nether Bricks & variants
• Added Red Nether Bricks & variants
• Added Prismarine Bricks & variants
• Added Purpur Block & variants
• Added Quartz, Smooth Quartz, etc. etc.
• Added Soul Sand
• Added Soul Soil
• Added Sponge and Wet Sponge
• Removed the Spyglass model change, since it's now a 2D sprite as of 21w10a