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.
@aseth1 @sherm1  There have been a few discussions highlighting the difference between a point and a station.  What I recall was that a Station means a point fixed on the articulating multibody system.  It's the specific subset of points that you can apply forces to, like pathpoints.  A floating point would be something else.

I agree that we may consider Markers to be associated with any point, even one's that aren't fixed to bodies/frames.  I think that's a future discussion though.  I just patched Marker as is.