The concept of environments.
Merge pull request #311 from CraftStone/master

The concept of environments.
Add getter for entity class in EntityType
Expand Block/Item interfaces
Merge pull request #309 from Deamon5550/feature/block-expansion

Expand Block/Item interfaces
World Generator API
Add Aerial, Ambient, Aquatic, and Boss.
Update art names to match minecraft names - Thanks @AIOOB
Fix Javadoc error in EntityMoveEvent.
Add extended particles api. (#323)
Remove FusedExplosive#ignite as a FusedExplosive is already ignited when spawned.
Add IgnitableExplosive to represent entities that can be ignited.