Prepare for concurrent mode

In concurrent mode, renders can be discarded, which means they'll never be committed to the DOM (or whatever native host). There are potentially other issues as well (see [here](https://github.com/dai-shi/will-this-react-global-state-work-in-concurrent-mode)).

Currently, the `withAuto` and `useAuto` functions cause side effects during render, which means memory leaks **will** occur in concurrent mode.