message: doc(windows): update how to handle MSVS 2019
diff: @@ -48,12 +48,12 @@ cd /c/lib
  @code{.bash}
  #!/bin/bash -e
  myRepo=$(pwd)
  -CMAKE_CONFIG_GENERATOR="Visual Studio 14 2015 Win64"
  +CMAKE_GENERATOR_OPTIONS=-G"Visual Studio 16 2019"
  +#CMAKE_GENERATOR_OPTIONS=-G"Visual Studio 15 2017 Win64"
  +#CMAKE_GENERATOR_OPTIONS=(-G"Visual Studio 16 2019" -A x64) # CMake 3.14+ is required
  if [ ! -d "$myRepo/opencv" ]; then
  echo "cloning opencv"
  git clone https://github.com/opencv/opencv.git
  - mkdir -p Build/opencv
  - mkdir -p Install/opencv
  else
  cd opencv
  git pull --rebase
  @@ -62,16 +62,17 @@ fi
  if [ ! -d "$myRepo/opencv_contrib" ]; then
  echo "cloning opencv_contrib"
  git clone https://github.com/opencv/opencv_contrib.git
  - mkdir -p Build/opencv_contrib
  else
  cd opencv_contrib
  git pull --rebase
  cd ..
  fi
  RepoSource=opencv
  -pushd Build/$RepoSource
  -CMAKE_OPTIONS='-DBUILD_PERF_TESTS:BOOL=OFF -DBUILD_TESTS:BOOL=OFF -DBUILD_DOCS:BOOL=OFF -DWITH_CUDA:BOOL=OFF -DBUILD_EXAMPLES:BOOL=OFF -DINSTALL_CREATE_DISTRIB=ON'
  -cmake -G"$CMAKE_CONFIG_GENERATOR" $CMAKE_OPTIONS -DOPENCV_EXTRA_MODULES_PATH="$myRepo"/opencv_contrib/modules -DCMAKE_INSTALL_PREFIX="$myRepo"/install/"$RepoSource" "$myRepo/$RepoSource"
  +mkdir -p build_opencv
  +pushd build_opencv
  +CMAKE_OPTIONS=(-DBUILD_PERF_TESTS:BOOL=OFF -DBUILD_TESTS:BOOL=OFF -DBUILD_DOCS:BOOL=OFF -DWITH_CUDA:BOOL=OFF -DBUILD_EXAMPLES:BOOL=OFF -DINSTALL_CREATE_DISTRIB=ON)
  +set -x
  +cmake "${CMAKE_GENERATOR_OPTIONS[@]}" "${CMAKE_OPTIONS[@]}" -DOPENCV_EXTRA_MODULES_PATH="$myRepo"/opencv_contrib/modules -DCMAKE_INSTALL_PREFIX="$myRepo/install/$RepoSource" "$myRepo/$RepoSource"
  echo "************************* $Source_DIR -->debug"
  cmake --build . --config debug
  echo "************************* $Source_DIR -->release"
  @@ -82,15 +83,15 @@ popd
  @endcode
  In this script I suppose you use VS 2015 in 64 bits
  @code{.bash}
  -CMAKE_CONFIG_GENERATOR="Visual Studio 14 2015 Win64"
  +CMAKE_GENERATOR_OPTIONS=-G"Visual Studio 14 2015 Win64"
  @endcode
  - and opencv will be installed in c:/lib/install
  + and opencv will be installed in c:/lib/install/opencv
  @code{.bash}
  --DCMAKE_INSTALL_PREFIX="$myRepo"/install/"$RepoSource" "$myRepo/$RepoSource"
  +-DCMAKE_INSTALL_PREFIX="$myRepo/install/$RepoSource"
  @endcode
  with no Perf tests, no tests, no doc, no CUDA and no example
  @code{.bash}
  -CMAKE_OPTIONS='-DBUILD_PERF_TESTS:BOOL=OFF -DBUILD_TESTS:BOOL=OFF -DBUILD_DOCS:BOOL=OFF -DBUILD_EXAMPLES:BOOL=OFF'
  +CMAKE_OPTIONS=(-DBUILD_PERF_TESTS:BOOL=OFF -DBUILD_TESTS:BOOL=OFF -DBUILD_DOCS:BOOL=OFF -DBUILD_EXAMPLES:BOOL=OFF)
  @endcode
  -# In git command line enter following command :
  @code{.bash}
  