Merge branch 'dev' into 1.13, and partial bug fixes

# Conflicts:
#	src/main/java/net/glowstone/GlowWorld.java
#	src/main/java/net/glowstone/block/blocktype/BlockSponge.java
#	src/main/java/net/glowstone/command/minecraft/TeleportCommand.java
#	src/main/java/net/glowstone/entity/GlowEntity.java