first stab at adding concurrency (but we're still only fetching one URL);
Merge branch 'dev' into feature-concurrency
changed the "state" option to "logs", to avoid confusion (this makes more sense anyway);
recur on state, not index;
I was forgetting to provide it with the state to update to;
minor variable name change;
removing an unnecessary local binding;
some more minor stylistic changes;
making sure the URL fetching happens on its own thread, and updates the state in another thread;
this isn't very useful yet, but it will be once we start checking multiple URLs concurrently;