DQ2Mat:

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   Finds the derivative of a transformation matrix in terms of quaternions

   Since version 2.
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   Form:
   dM = DQ2Mat( q, qDot )	
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   Inputs
   ------
   q       (4,1)  Equivalent quaternion
   qDot	(4,1)  Quaternion derivative

   -------
   Outputs
   -------
   dM      (3,3)  Derivative of orthonormal transformation matrix

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