Merged - added gradient method

.gitlab-ci.yml

CMakeLists.txt

FindBoost.cmake

build.bat

build.sh

build_scripts/linux/build_boost_gcc.sh

build_scripts/linux/download_dependencies.sh

build_scripts/linux/linux_clean_after_examples.sh

build_scripts/linux/linux_clean_after_lib.sh

build_scripts/linux/linux_clean_after_tests.sh

build_scripts/linux/linux_clean_examples.sh

build_scripts/linux/linux_clean_garbage.sh

build_scripts/linux/linux_clean_lib.sh

build_scripts/linux/linux_gcc_build_x64_debug_local.sh

build_scripts/linux/linux_gcc_build_x64_debug_system.sh

build_scripts/windows/win_VS_build_x64_debug.bat

build_scripts/windows/win_VS_build_x64_release.bat

build_scripts/windows/win_clean_after_examples.bat

build_scripts/windows/win_clean_after_lib.bat

build_scripts/windows/win_clean_after_tests.bat