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.
I should have qualified that as the ModelComponent maker of this new Joint type I should be able to collect, organize SimTK elements as I choose. As it stands I have no way of exposing a frame of interest other than creating OpenSim::Body and having it backed by a MobilizedBody (by index). Yes the Simbody system is throw away, but that is why you have to create the system before you run it. In no way should the mobilized body index be serialized- it is only defined at addToSystem.

The bottom line is that RigidFrame being bound to a OpenSim::Body is way to restrictive. We have Body and FixedFrame that are already bound to OpenSim::Body, why does the abstract RigidFrame need to be restricted in this way too? Seems silly to me. The computation requirement is access to the underlying MobilizedBody and that's all the abstract class should restrict.