* access proxies for any instance of klass * remove stubs from "running" instances * pass recorder into chains to register stubs * reduce lookup cost of proxies by klass * record stubs used * remove just the stubs recorded by any instance * switch from for..in to each * allow unstubing of instances that are a sub class * refactor lookup for subclass * Improve doc string. * "local instance" didn't really give me the right * sense for what this was testing. * Improve space spec. - The old spec only checked the number of proxies returned, and didn't actually check that it returned the right ones. - The old spec only tested who were instances of the given class, and did not check instances of subclasses.