Added sample links in documentation for python2, ocl and gpu

modules/core/doc/clustering.rst

@@ -70,6 +70,8 @@ attempts to 1, initialize labels each time using a custom algorithm, pass them w
 
    * : An example on K-means clustering can be found at opencv_source_code/samples/cpp/kmeans.cpp
 
+   * : PYTHON : An example on K-means clustering can be found at opencv_source_code/samples/python2/kmeans.py
+
 partition
 -------------
 Splits an element set into equivalency classes.

modules/core/doc/operations_on_arrays.rst

@@ -1001,6 +1001,9 @@ All of the above improvements have been implemented in :ocv:func:`matchTemplate`
 
    * : An example using the discrete fourier transform can be found at opencv_source_code/samples/cpp/dft.cpp
 
+   * : PYTHON : An example using the dft functionality to perform Wiener deconvolution can be found at opencv_source/samples/python2/deconvolution.py
+   * : PYTHON : An example rearranging the quadrants of a Fourier image can be found at opencv_source/samples/python2/dft.py
+
 
 divide
 ------