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.
@sherm1 @aymanhab @aseth1 

Good.  Then you and I at least agree!  What Ayman and I have already done here supports Sherm's and my view of what a Station is.  If a station is fixed on the multibody system, then if must be fixed to a RigidFrame, not Frame.  That describes the current interface.