Rates2EulDot:

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   Converts angular velocity into 3-2-1 Euler angle rates. If only one
   input is given, the output is the transformation matrix.
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   Form:
   wEul = Rates2EulDot( e, w, n )
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   ------
   Inputs
   ------
   e		(3)    Euler angles
   w		(3)    Angular rates
   n   (1)    Orbit rate (for rotating frames only, optional)

   -------
   Outputs
   -------
   wEul		(3)    Euler angle rates

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   Reference: Hughes, Spacecraft Attitude Dynamics (1986), Table 2.2 p. 27
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