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

* Simulated Annealing for ANN_MLP training method

* EXPECT_LT

* just to test new data

* manage RNG

* Try again

* Just run buildbot with new data

* try to understand

* Test layer

* New data- new test

* Force RNG in backprop

* Use Impl to avoid virtual method

* reset all weights

* try to solve ABI

* retry

* ABI solved?

* till problem with dynamic_cast

* Something is wrong

* Solved?

* disable backprop test

* remove ANN_MLP_ANNEALImpl

* Disable weight in varmap

* Add example for SimulatedAnnealing

- drop dependency on 'import cv2', use pyopencv_signatures.json instead
- try to make generator idempotent

Added Python setup docs for Ubuntu Machines (#10056)

Resolves - https://github.com/opencv/opencv/issues/9928

clarify some passages, fix grammar errors