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.
Why is this necessary here? Why should RigidFrame  have a Transform to the MobilizedBody? - it is the OpenSim representation of the MobilizeBody. And we already have a derived class that is FixedFrame that is the arbitraty "offset" represented by a fixed Transform.