Add horse mob option JumpStrength

Summary

Add a mob option for horse-like mobs that allows to set the default jump strength of the horse.

Usage

This would allow users to create horse-like entities with consistent and more customised movement behaviours.

Value

In mobs/exampleHorse.yml:

exampleHorse:
   Type: HORSE
   Options:
     JumpStrength: 0.3

Priority

Medium priority, the feature has low implementation complexity, requiring only a new mob option and a simple method call at mob spawn time. It provides significant improvements for servers that want consistent or customised mount behaviours. It also fits well with the existing options as other horse-specific options are already supported.

Implementation

This can be implemented by adding a new mob option (JumpStrength: <double>) that applies to entities that extend the AbstractHorse class through the method setJumpStrength(double strength).