Structural frame extensions

[ChrisClems]

I don't even know where to start here. Just make it less bad.

[ChrisClems]

Structural frame objects are misleadingly named and are "assemblies" of frame "sections" or "segments" depending on which member you're using.

Frame sections can only be obtained from a frame using a ref that returns an array of sections with a section count via out. (build enumerable?)

[ChrisClems]

Extension method on StructuralFrames that returns a list of StructuralFrameSection objects (or segment? The SE API uses both interchangably).

StructuralFrameSection properties:

Side angle 1
Side angle 2
End angle 1
End angle 2
Offsets and rotations (create new coordinate class for X/Y/Z)

Side and end angles are not returning expected values.