[connection] handle and explicitly life cycle on Connection
Like ClientConnection, Connection object need to be explicitly started and stop.
They aims to be used as context manager.
from os.path import join
assert __file__.endswith(join('scripts', 'script3.py')), __file__
assert '__main__' == __name__, __name__
assert ['-vd', '-f', 'FILE.TXT'] == __args__, __args__