Use PureRenderMixin

[mlsteele]

Almost all of the components in this app are pure.
We should use PureRenderMixin

Also, it would be interesting to benchmark various UI changes to see whether this makes a difference. It still feels a bit slow on mobile.

Maybe doing "onChange -> rerender app" is slow.
Try using setprops on the outer component (forcing the update against PureRenderMixin) instead.
"Calling React.renderComponent() again on the same node is the preferred way to update a root-level component."

http://facebook.github.io/react/docs/component-api.html#forceupdate

[mlsteele]

Render is async. How should I measure how long it takes?