Add Java and Python code for the following features2d tutorials: Harris corner detector, Shi-Tomasi corner detector, Creating your own corner detector, Detecting corners location in subpixels, Feature Detection, Feature Description, Feature Matching with FLANN, Features2D + Homography to find a known object. Use Lowe's ratio test to filter the matches.

Add Java and Python code for the following imgproc tutorials: Affine Transformations, Histogram Equalization, Histogram Calculation, Histogram Comparison, Back Projection.

Add Java and Python code for the following imgproc tutorials: Canny, Remap, threshold and threshold inRange. Use HSV colorspace instead of RGB for inRange threshold tutorial.

Fix publication date of "Computer Vision Face Tracking for Use in a Perceptual User Interface" from 1988 to 1998.

* Custom deep learning layers support

* Stack custom deep learning layers

  * remove NVidia and Nvidia
  * replace Cuda with CUDA
  * keep the letters for API

Correct a mistake in {js,py}_table_of_contents_histograms.markdown (#11260)

* Update py_table_of_contents_histograms.markdown

"Learn to find and draw Contours" => "Learn the basics of histograms"

* Update js_table_of_contents_histograms.markdown

Corrected a seemlingly wronged line of copy in the python documention js_table_of_contents_histograms.markdown

"Learn to find and draw Contours" => "Learn the basics of histograms"

project is not active anymore

Apparently the blog has been updated and the URL has changed, it is still there though.

OpenCV 3.4.1

Found via `codespell`

Found via `codespell -q 3 --skip="./3rdparty" -I ../opencv-whitelist.txt`

Documentation generation refactoring (#10621)

* Documentation build updates:

- disable documentation by default, do not add to ALL target
- combine Doxygen and Javadoc
- optimize Doxygen html

* javadoc: fix path in build directory

* cmake: fix "Documentation" status line

JS examples - FFT didn't work for non-square images because rows/cols were switched, Histogram example misspelled point

* Update samples

* Update calib3d.hpp

* Update calib3d.hpp

* Update calib3d.hpp

* Update calib3d.hpp

OpenCV 3.4.0-rc