now saving speed when storing a horse

Use https://dl.bukkit.org/downloads/craftbukkit/get/02389_1.6.4-R2.0/craftbukkit.jar as dependency instead of Bukkit.
If you want to support another version, you have to use the according CraftBukkit build.
This is a breaking change with every update, since there is no Bukkit API to read or modify an entity's speed.