Each actor get's it's ID passed

Each actor gets passed its ID as its first argument.
Each actor can send a message by printing to its stdout.
This can either be a data message or a props message. A data message gets routed to the actor with the given id.
A props message takes the arguments from the props and spawns the executable according to the props.
Each actor can print to stderr in order to log something.
To receive messages, an actor has to read from its stdin. There are currently two types of messages that can get sent
to an actor.
A spawned message, telling the actor if spawning of a props succeeded or failed and the id of the spawned actor.
Or a data message from another actor.