Add Part 1 of Passive Entities [Entities]

[gabizou]

This is a smaller PR that bases the entirety of the entities feature for Glowstone.

The entities implemented in this PR are:

• [x] GlowBat
• [x] GlowChicken
• [x] GlowHorse
• [x] GlowPig
• [x] GlowRabbit
• [x] GlowSheep

The following are implementations of various interfaces required by the above entities (and some other entities to be added after this PR is merged):

• [x] GlowTameable
• [x] GlowAgeable
• [x] GlowAmbient
• [x] GlowAnimal

Included are the storages for the implemented entities with the following:

• [x] BatStore
• [x] AgeableStore
• [x] CreatureStore
• [x] TameableStore
• [x] HorseStore
• [x] PigStore
• [x] RabbitStore
• [x] SheepStore

This PR depends on GlowstoneMC/Glowkit#31

[gabizou]

This PR is an evolved version of #282. The old PR will remain open as a marker/todo list.

[dequis]

Merged thing https://github.com/dequis/Glowstone/compare/pr-599

[gabizou]

Sorry about the really long wait. @turt2live It's been a relatively busy month, sorry for the delay.