Start new session and prepare environment for new row editing process

		:return: None

def start_session(self):
		""" Start new session and prepare environment for new row editing process

		:return: None
		"""
		self.__current_row = ''
		self.__history_mode = False
		self.__editable_history = deepcopy(self.__history)
		self.__prompt_show = True
		self.refresh_window()