Item Detector Rail (Chest carts and players)

The suggestion I'd like to make is for a detector rail. This item will do the following.

- Check to see if any item in a chest cart matches its internal inventory of 1 slot. (includes named items)

- If 1 item in the chest cart matches the internal inventory it outputs a redstone signal.

- If the chest cart does not have a matching item the rail will emit no redstone signal.

- If a redstone signal is applied to the rail it checks for players. 

- If the player is found and no item is in the internal inventory it outputs a redstone signal.

- If a player is found and does not have an item matching the one in the Item Detector Rail the rail will emit no redstone signal.

This block is a useful for automation of minecarts in the following examples.

A mail system using the internal inventory with a named item for each destination. if the track is a loop then the cart would circle around until it runs across an item detector rail with a matching item(named items included.) this could be used to switch a rail allowing the cart to arrive at its destination,

The player detection functionality can be used to allow a player only exit for a minecart track this allows for an automated mail system or sorting system to accommodate players without requiring to separate lines of track. A single line of track can be used for both freight and passenger travel.

An item like this can allow for an functional transportation system in minecraft that is more than just point to point.

Praise GOD!