add `state.bind` and `state.fix`

Portends deprecation of `state.method`.
remove `state.method`
remove specialized `express` cloning for methods

With deprecation of the `state.method` implementation, cloning methods
works the same way as cloning items from any other category.
add experimental `__dispatch_table__` object to realized states

Consumers of this table (`method`, `apply`) will check for its
existence first, so this should be safe to null or comment out without
any breakage....
rewrite `method`, `addMethod`, `apply`

Implements subjective, owner-by-default binding for methods,
deprecating the state-by-default context binding pattern used
previously.

Supports the “state-bound” and “state-fixed” function boxing pattern
provided by `state.bind` and `state.fix`.
bugfix, cleanup
interpret boxed bound- and fixed-function objects as methods
micro-opt: test against value access, not key lookup

Should only use `key of` (`in`) to differentiate against possibility of
`key: undefined` — `obj[key]` is highly optimized (15-20x faster) in v8
revert nonexistent method lookup to return undefined

Maintains consistency with other categories’ lookup methods.
fix inheritance via superstate of boxed methods
automatic dispatchers per-instance tentatively deemed unnecessary
test bind/fix against inheritance via protostate and superstate
bury dispatch table into StateContent
allocate dispatch table on-demand
cleanup
expand bind/fix to use private constructors for boxing
for now put dispatch tables behind an options flag

Should wait until after implementation and testing of an `invalidate`
event that inheritors can use to subscribe to events for mutation or
deletion of methods of superstates/protostates
Merge pull request #1 from nickfargo/subject-binding

Subjective context binding with optional state-binding