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.
> (Simbody uses the "find" prefix to mean "calc, but very cheap"; probably doesn't make sense to make that distinction in OpenSim unless it is already in use -- "calc" would be fine.)

@sherm1  I like this find = "calc cheaply".  Doesn't that apply to getBodyTransform(state) as well, or is the distinction that the state is already realized to position so it's X_GB is already cached?