Patch 0.14a - hot fix

Some new bugs have been introduced with the new patch, This hotfix should fix them up.

Changes
- Contrails have decreased opacity and higher particle count
- Reduced upgrade costs for the Swordfish
- Updated lighting calculations on the Swordfish

Bug Fixes
- Swordfish newly bought weapons couldn't be equiped
- B17 when equiped couldn't be spawned in missions
- B17 turrets wouldn’t equip when purchased
- Elevators on the B17 weren’t joined on the same pivot causing an offset in the model
- Mission 5 in Africa failed to load terrain
- B17 mission progression was bugged