Sage's airship addon

Sage informed us that he has released his airship addon.

Features:

- 48 passenger capacity
- Top speed of 72 kph
- 25 mm cannon with HE and AP ammo
- FAB 200 freefall bombs
- Animated propeller blades
- Rappelling ropes drop from the Cabin when flying below 6 meters
- Anchor slows airship down to 6 kph when flying below 20 meters
- Full rudder control.