A note on fuel tank priority

One limitation on the use of the "priority" tag for fuel tanks: The priority number can't be greater than the number of tanks. For example, the Thunderbirds F-4E model only had one fuel tank defined, and it had a priority of 2, which resulted in it not feeding. One solution is to change the priority to 1. A better solution is to add the external tank definitions, as in the other F-4's. It's not necessary that the tank definitions in the FDM match the tank models actually installed on the model, so if the airplane might carry a certain external tank, go ahead and add the definition for it.

I'll be adding tank definitions for the external tanks that N-SCOT made for the A-7E , even though they aren't installed on my current A-7E model.