Merge branch 'release/v18.06.0' into stable

.gitlab-ci.yml

cmake/Testing.cmake

cmake/WarningLevels.cmake

cmake/cppcheck.cmake

cmake/cpplint.cmake

cmake/suppress_warnings.hpp.in

conanfile.py

demos/combustion_demo/src/combustion_demo.cpp

...ombustion_demo/src/vr_controller_interaction_behavior.cpp

...ombustion_demo/src/vr_controller_interaction_behavior.hpp

demos/viewer/src/viewer.cpp

demos/viewer/src/viewer_system.hpp

demos/viewer/src/vrcontroller_navigation_behavior.cpp

demos/viewer/src/vrcontroller_navigation_behavior.hpp

library/phx/core/engine.hpp

library/phx/core/entity.hpp

library/phx/core/scene.hpp

library/phx/display/display_system.hpp

library/phx/display/display_system_openvr.cpp

library/phx/display/display_system_openvr.hpp