Alpha-2 of Dynmap v3.0 for Spigot 1.8.9-1.13.1

Changes since alpha-1:

• Added support for v1.13.1 (v1.13 support is still present, but will be removed next release)
• Fixed missing textures for blue wool blocks
• Fixed redstone wire rendering in v1.13+
• Fixed door models in v1.13+
• Fixed huge mushroom rendering in v1.13+
• Fixed glass pane and iron fence models in v1.13+
• Fixed vine models in v1.13+
• Fixed prismarine stairs, slabs in v1.13+
• Fixed fence gate models in v1.13+
• Fixed broken cave rendering in v1.13+ (more than one type of air in v1.13...)