“... the wilful doing of a dangerous and reckless act with wanton unconcern and indifference to the consequences and perils involved and as to whether anyone is harmed or not, is just as worthy of punishment, when the harmful result ensues as is the express intent to kill itself. Such state of mind [is treated] as just as blameworthy, just as anti-social and just as truly murderous as the specific intents to kill and to harm.”