Hyper's Hexcast Addon

Just a little addon for HexCasting by Petrak@. Adds the following patterns:

• Inclining Prfn: Get a list of integers within the Interval [0,n) (equivalent to Python's range).
• Rider's Prfn: Get the entity that a given entity is riding (e.g. a minecart).
• Jockey's Prfn: Get a list of entities that are riding an entity.
• Driver's Prfn: Return whether an entity is controlling the entity it's riding.
• Mount spell: Cause an entity to begin riding another entity.
• Dismount spell: Cause an entity to stop riding the entity its riding.