function reloadChangedDocs() {
        // Reload each doc in turn, and once all are (async) done, signal that we're done
        return Async.doInParallel(toReload, reloadDoc, false);
    }
Reloads all the documents in "toReload" silently (no prompts). The operations are all run
in parallel.
@return {$.Promise} Resolved/rejected after all reloads done; will be rejected if any one
     file's reload failed. Errors are logged (by reloadDoc()) but no UI is shown.