Add a BiomeTypes interface
Add methods in ServerInterface to retrieve the implemented BiomeTypes
Add a getBiome method to LocalWorld and subclasses
Add /biomeinfo & /biomelist commands
Add a BiomeTypeMask
Closes#181
This keeps things simpler by not dealing with redundant implementations
for single change and multiple changes.
This also let regions handle related changes in a more efficient way
(for example recalculates region components only when needed).