Merge branch 'release/v18.05.0' into stable

.gitattributes

.gitlab-ci.yml

cmake/WarningLevels.cmake

cmake/assign_source_group.cmake

cmake/suppress_warnings.hpp.in

conanfile.py

demos/CMakeLists.txt

demos/combustion_demo/CMakeLists.txt

demos/combustion_demo/debug.ico

demos/combustion_demo/phoenix.ico

demos/combustion_demo/resource_file.rc

demos/combustion_demo/src/combustion_demo.cpp

demos/combustion_demo/src/desk_behavior.cpp

demos/combustion_demo/src/desk_behavior.hpp

demos/combustion_demo/src/desktop_navigation_behavior.cpp

demos/combustion_demo/src/desktop_navigation_behavior.hpp

...combustion_demo/src/vr_controller_navigation_behavior.cpp

...combustion_demo/src/vr_controller_navigation_behavior.hpp

demos/viewer/src/navigation_behavior.cpp

demos/viewer/src/navigation_behavior.hpp