Unity Coaster testing C#

UnityCoaster Update 002:

- Fixed orientation issues with procedural mesh by using a 'extrude' object to calculate the position of the vertices.  Used extrude_object.TransformPoint(Vector3 vert_pos) to get the world space position of the extrude vertex and then Inversed that method using the transform of the procedural mesh.

- Made a seperate dockable Unity EditorWindow for the controls.
https://docs.unity3d.com/ScriptReference/EditorWindow.html

- Added auto selection after adding a new track piece.

Next:
- Make track pieces auto adjust/fit.
- Make sure all pieces are still editable.
- Add quick rotation buttons. (90 degree turns etc.)
- Create a more realistic rollercoaster mesh. (Including rails etc.)