Matt ayman frames

Redo of the merge of Frame, RigidFrame, FixedFrame, Station and Marker ModelComponents along with code to convert Marker to new format for serialization/deserialization and inclusion of FrameSet in model.
@sherm1 @msdemers @aseth1 or @chrisdembia Please review and let us know your feedback.
Can this be stated in the documentation explicitly, perhaps including Ajay's shoulder example? It'd be too bad if we developed the code with a use case in mind and no one ever learns that they can use the code in that way.