Generalise IV:10 to cover all rideable entities

The rule previously would have permitted the use of horses or saddled pigs as a way of bypassing bedrock on a lane edge. This change makes this illegal.
Clarification of IV.10.

This prevents bedrock bypass exploits such as clicking a minecart which is partially in the void to bypass a barrier.
Prevent certain bedrock bypass exploits
Merge pull request #1 from itsmartin/gh-pages

Ruleset update to prevent certain bedrock bypasses