#29 fix race condition related to retrieving organizations

Closes #29 (closed)

If you read over #29 (closed), you'll see that the primary goal was to make sure that retrieveOrganizations didn't happen until the RoutesRecognized event in the Router lifecycle happened. In addition, I need a safeguard to ensure that retrieveOrganizations doesn't happen more than once. RoutesRecognized will fire when you change pages, but as of today we don't need to re-query the organizations API when that happens.

This MR accomplishes that. I'm not sure I did it in the right spot or in the right way, though.

1. I have BehaviorSubject stuff in a component, when we usually do that in a service. How bad is that? Felt wrong to start a RouterService for two booleans.
2. There is routeParams stuff in organizations.service already (although it's not in the BehaviorSubject for some reason), and we already import org service to call retrieveOrganizations. So there's a strong case to put routeParams into the org service's BehaviorSubject and import it into app component.
3. However, app.component doesn't really care what routeParams are; it only cares if a certain router event fired. We already had one condition like this: isLoggedIn. Now we have three: isLoggedIn, routesRecognized, and retrieveOrgsFiredOnce. They're annotated.