in accessor method, fall back to `root` if a `current` state is not yet available
initial working implementation of parastate declarations and computation of monotonic linearization of `State`s
simplify head/tail concatenation
rename property `linearization` to `order`, move from `Metaobject` to `State`; inline `linearize` function
cleanup
remove unused params
add `state.extend` function
rename expressions; use `state.extend` notation
add test for all of proto-, para-, and super- together
add parastate resolution test
implement parastate method resolution
rename param to `returnBoxed`
cleanup
override `linearize` in `Transition`

- a transition does not have parastates, and inherits only from the
superstate to which it is attached
update links to section title "Object model" in docs
update links
change output of `linearize` to return the array directly

- Shifts responsibility of copying and avoiding mutation of the array
to the iteration
- Allows the linearize-on-demand pattern to be used during lookups
without wasting an allocation
implement parastates and linearization over the Data methods
implement parastate resolution over events in `State::emit`
add synopses for `has`, `get`, `delete`