Revamp aerodynamic interactions

[exocetfalling]

• Currently handled in the main aircraft script
• Proposal to make aerodynamic surfaces rigid bodies, connected by joints and controlled by a central root part
• Increases maintainability and flexibility since any number of surfaces can be added and they'll all interact via the joints
• More logical and less... painful stuff in the CSG mesh
• Cons: it's quite a lot of work

[exocetfalling]

See Blade Element Theory

[exocetfalling]

Nearing completion, with a few changes:

• Many RigidBody nodes in scene and connected by joints turned out to have insufficient strength
• Performance impact was also significant

Hence, we replaced the implementation with the following:

• One AeroBody node for the usual forces (weight etc.)
• Multiple AeroSurface nodes to handle each aerodynamic surface
• Lift/drag calculations are handled by the AeroSurface nodes, then accessed by the AeroBody
• The AeroBody adds all the forces from each AeroSurface

Because of the success of this implementation, it's likely that AeroJoint and AeroElement will be removed.