Updated rst configuration to read OpenCV version from sources; fixed several sphinx' warnings

modules/imgproc/doc/motion_analysis_and_object_tracking.rst

@@ -163,23 +163,28 @@ The function performs the following equations
 *
     Next it computes the forward DFTs of each source array:
     .. math::
+
         \mathbf{G}_a = \mathcal{F}\{src_1\}, \; \mathbf{G}_b = \mathcal{F}\{src_2\}
+
     where
     :math:`\mathcal{F}` is the forward DFT.
 
 *
     It then computes the cross-power spectrum of each frequency domain array:
     .. math::
+
         R = \frac{ \mathbf{G}_a \mathbf{G}_b^*}{|\mathbf{G}_a \mathbf{G}_b^*|}
 
 *
     Next the cross-correlation is converted back into the time domain via the inverse DFT:
     .. math::
+
         r = \mathcal{F}^{-1}\{R\}
 *
     Finally, it computes the peak location and computes a 5x5 weighted centroid around the peak to achieve sub-pixel accuracy.
     .. math::
-        (\Delta x, \Delta y) = \texttt{weighted_centroid}\{\arg \max_{(x, y)}\{r\}\}
+
+       (\Delta x, \Delta y) = \texttt{weighted_centroid}\{\arg \max_{(x, y)}\{r\}\}
 
 .. seealso::
     :ocv:func:`dft`,