Universal Intrinsics: aligned v_pack behavior on different platforms, fixed 64-bit register on ARM, added more saturate_cast variants

Fix a code indent bug:   cv2.imshow("detected lines", cdst)

- fix compilation on Apple (undefined 'oclpath')
- don't warn on OPENCV_OPENCL_RUNTIME=disabled

Entries with the same platform name, the same device name and with different driver versions
are assumed obsolete.

Following were the errors in the digits_video.py
     1 ) The code was not working because data type of x was float however in "cv2.rectangle" we require integer .
     2 ) After pressing the "esc" button the image windows did not destroy
So I amended following things:
     1 ) ~converted data type of x to int.~ Used Python integer division (//)
     2 ) used cv2.destroyAllWindows() to close all windows after the press of "esc" by user.

* Adding threading in calibrate.py

* samples: update calibrate.py

It allows umat buffers used in net forward interface
Signed-off-by: Li Peng <peng.li@intel.com>