- `StateMachine::new(MachineState)` has been replaced with

`StateMachine::default()`, and you must insert the initial state manually

- `MachineState` requires `Component` now instead of `Bundle`

- `StateMachine`'s

`trans_builder(Trigger, Fn(&Trigger::Ok) -> Option<MyNextState>)` is now

`trans_builder(Trigger, Fn(&MyCurrentState, Trigger::Ok) -> Option<MyNextState>)`,

so you can take information from the current state when building the next!

- `StateMachine` no longer tracks the current state, so you may add and remove

state components manually, as long as it's still in one state. Manual state

changes won't trigger `on_enter` etc events. States that aren't used in any

transitions can be registered manually with `StateMachine::with_state`, else it

will think it isn't in a state and panic.

- Replaced `StateMachine`'s `insert_on_enter(Bundle)` and `remove_on_exit()`

with the more versatile `on_enter(Fn(&mut EntityCommands))`,

`on_exit(Fn(&mut EntityCommands))`, `command_on_enter(Command)`, and

`command_on_exit(Command)`

- `Trigger`s may be combined with combinators `not`, `and`, and `or`

- `Trigger::trigger` accepts `ReadOnlySystemParam` instead of `&SystemParam`, so

you can use `EventReader`, `Local`, etc in your triggers!

- `StateMachine::set_trans_logging` sets whether to log state transitions for