Merge branch 'emper-shutdown' into 'master'

emper/Common.hpp

emper/Context.cpp

emper/Context.hpp

emper/ContextManager.cpp

emper/ContextManager.hpp

emper/Dispatcher.cpp

emper/Dispatcher.hpp

emper/Emper.cpp

emper/Emper.hpp

emper/Runtime.cpp

emper/Runtime.hpp

emper/include/emper.hpp

emper/lib/adt/RwLockUnboundedQueue.hpp

tests/RuntimeDestroyTest.cpp

tests/meson.build