(Attention, not savegame compatible!)

- added the Rumpler C and the Breguet 14
- added a pilot ranking list
- added a little personnel management at the airfields
- major performance improvements and thus significantly less stuttering
- loading already loaded savegames should now work as expected
- favorite paintings on airfields are now independent of aircraft type and aces should keep their unique paintings
- many squad ai behaviors have been improved (hopefully for the better), e.g. mysterious crashes have almost disappeared
- shadows changed so they create more contrast
- added particle effects when airplanes hit the ground
- and as always a lot of smaller fixes and improvements

still a good way to go, but the end is getting in sight