Part III: Optional Modules

This part describes the main classes contained in the optional modules, where 'optional' means that you can opt out of them if you don't need them (you don't normally have to opt in to them if you want to use them, since they're defined as being part of the adv3Lite library as standard).

One of the optional modules, Actors will be left until later, when it will get a whole part to itself.