restructured repository based on following standards:

https://github.com/HW-Core/directory-structure

modules/dep/g3dlite/include/G3D/PhysicsFrameSpline.h

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+/**
+  @file PhysicsFrameSpline.h
+
+  @author Morgan McGuire, http://graphics.cs.williams.edu
+ */
+#ifndef G3D_PhysicsFrameSpline_h
+#define G3D_PhysicsFrameSpline_h
+
+#include "G3D/platform.h"
+#include "G3D/PhysicsFrame.h"
+#include "G3D/Spline.h"
+
+namespace G3D {
+
+/**
+ A subclass of Spline that keeps the rotation field of a
+ PhysicsFrame normalized and rotating the short direction.
+
+ \sa UprightFrameSpline
+ */
+class PhysicsFrameSpline : public Spline<PhysicsFrame> {
+public:
+    PhysicsFrameSpline();
+
+    /** Accepts a table of properties, or any valid PhysicsFrame specification for a single control*/
+    PhysicsFrameSpline(const Any& any);
+
+    /** Clear and then reset all values from the any */
+    PhysicsFrameSpline& operator=(const Any& any);
+
+    virtual void correct(PhysicsFrame& frame) const;
+    virtual void ensureShortestPath(PhysicsFrame* A, int N) const;
+};
+
+}
+
+#endif