Review swaps: xfoil, xrotor, avl

[Sandro Mani]

Hi,

I've posted the following package review requests:
- #1007539 - xfoil: Subsonic Airfoil Development System
- #1007540 - rotor: Design and analysis tools for propellers and windmills
- #1007541 - avl: Aerodynamic and flight-dynamic analysis of rigid aircrafts

They are all fortran/C applications with dead simple spec files (and 
beautiful handwritten Makefiles *cough*).

Happy to review packages in exchange.

Thanks,
Sandro