Finished 1.15 update, ready to release

[Shnupbups]

• Updated to 1.15.1
• Updated dependencies
• Switched GL calls to new RenderSystem calls
• Fixed Deceased Grass not being on the right RenderLayer
• Moved a lot of stuff out of TheHallowClient into more specific classes
• Fixed Deadwood Signs being completely broken
• Fixed Infusion Altars and Pillars wiping NBT data from items
• Fixed Infusion Altars and Pillars being massively oversized in the player's hand
• Re-enabled the Pumpkin Ring working on Pumpkin Pie blocks
• Changed the Deadwood Planks texture to better match the vanilla planks textures
• Added Coarse Tainted Sand which creates the previously unused upward bubbles in Witch Water
• Made Witch Water translucent
• Suppressed deprecation warnings
• Maybe other things I forgot that I did? idk

[Shnupbups]

@Boundarybreaker This PR already updates LibCD to the latest version, including changing all the calls to the newer, un-deprecated versions.