Trying to put something simple together...
System that shows the added shields
http://k8055.info/arduino/
Now to make the function that can check if there are multiple on the same pin.
And the system is almost done. The first shield will be reference for the following, and they will then be marked with red if they already are used, or marked with green if there are optional positions.
Some of the next will be to make the function where it is possible to select which shields you want to stack.