tinkering with examples
ensure transitioning works at the same route

need the component to remount when transitioning
from /foo/123 to /foo/321, so we put the key
on the deepest matched route
little more work on address book example
messing with examples some more

- addressbook -> master-detail

- partial app file renaming
simple master detail example
make active respect same route but new props

previously all links to the same route would show
as active, even if the props didn’t match
README