dillon1000/react

Attempt to simplify/fix warnAndMonitorForKeyUse

> The two callers of this function have different warning configs
> internally (static_upstream/core/createWarning.js) so we can't sync it
> like this without changing behavior. We should just split this out
> into two separate warning calls probably – this code is a little
> overabstracted.

https://github.com/facebook/react/pull/4021#discussion_r31690020
@spicyj

I think completely removing warnAndMonitorForKeyUse is a bit difficult, without
duplicating a ton of code. This at least ensures that the format string passed
to `warning` is unique. Plus, because the FB internal code in question only
matches the beginning of the format string, I think there should be zero
internal changes that need to be made to support this refactor.