logValues and perhaps other parameters are passed down into the <input> tag

[ericblade]

render() spreads ...this.state.customProps into to allow for consumers to pass in any parameters they want to to the underlying input mechanism.

prepareProps does not account for (at least) the logValues prop. We should also harden it, so that if any additional properties are added to CurrencyInputProps but are not caught in prepareProps, that we get some kind of build warning/error? is that possible?