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   A stellar attitude determination system.
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   Form:
   [q, b, p] = AttDet( angInc, q, dT, b, p, Q, r, qBToS, starDataMeas, starData, fScale, init )
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   Inputs
   ------
   angInc       (n,1)     Angular increments
   q            (4,1)     Attitude quaternion
   dT           (1,1)     Time step
   b            (3,1)     Bias
   p            (6,6)     State covariance matrix
   Q            (6,6)     State noise covariance
   r            (1,1)     Measurement noise
   qBToS        (4,1)     Quaternion from body to sensor axes
   starDataMeas (3,m)     Vector of [intensity;xloc;yloc]
   starData     (1,1)     Star Data
                          .starMatrix (4,n)     Star catalog containing n stars stored as [intensity;u] or
                          .starID     (1,m)     Identified stars
   fScale                 Sensor scale factor
   init         (1,1)     Initialize if 1

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   Outputs
   -------
   q            (4,1)     Attitude quaternion
   b            (3,1)     Bias
   p            (6,6)     State covariance matrix

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