Add Horse API. Adds BUKKIT-4424

API has been added to interface with Horses and to modify their inventories. A new event, HorseJumpEvent, has been added to be fired whenever a horse jumps.

This commit fixes BUKKIT-4393.
Spigot
EMC POM Changes
Water flow not trigger chunk loads

Make BlockFromToEvent default cancel if the flow would trigger a chunk load.
PlayerDeathEvent.getItemsToKeep

Exposes a mutable array on items a player should keep on death
Add a call helper to Event
Precise timings
Fix reset timings
EntityShootBowEvent consumeArrow API
ItemStack isSimiliar ability to skip durability check
Expose commandmap
Inventory Meta API
Check permissions on commands before executing them