Record the transition event in an automaton.

When we hit the end of a tesla lifetime, we will need to simulate a transition on each affected automata class. To do this, we need to know what symbol causes cleanup for that automaton.
Trivial: fix some Doxgyen warnings.
Split tesla_update_state().

There are now two separate functions: the high-level tesla_update_state looks up the right tesla_class, locks it and calls the low-level tesla_update_class_state, which does all of the automaton stuff.

This distinction is required to correctly support end-of-lifetime events.
Keep track of more lifetime state.

When we late-initialise an automata class, register it with the tesla_lifetime_state so that we know what to come along and clean up later.
Update tests for the New World Order.
Provide more informative FnTransition::ShortLabel.