Vanilla cart fix

Closes https://github.com/CovertJaguar/Railcraft/issues/220

Here's my hacky attempt at fixing vanilla replacement. It works but it's ugly and I hate it.
I was just tired of reloading my world for chest minecarts to function.
This is likely to result in carts created by worldgen (ie mineshafts) discarding their contents right? I might just remove this section and see if I can fix the dispensers.