Block method onEntityWalking

onEntityWalking is called when a Entity is walking on the block.

This function give 5 varibles:
 * 1) World world: This is the world that this event has occured
 * 2) Int x: Position in 'world' that this event has occured in X
 * 3) Int y: Position in 'world' that this event has occured in Y
 * 4) Int z: Position in 'world' that this event has occured in Z
 * 5) Entity entity: The Entity that halk walked on the block.

An example of this function is the following:

When a Enity (Mob,Player etc.) walks on this block, they will be forced up with a force of 2. Some experimenting is required to get optimal force.