Summary:
To allow smoother API changes for users we often deprecate props and keep them around for a while before removing them. Right now it is all done manually, this adds a consistent way to show a warning when using a deprecated prop.
This also adds a deprecation warning of the website generated from the deprecatedPropType.
<img width="643" alt="screen shot 2016-01-26 at 7 43 08 pm" src="https://cloud.githubusercontent.com/assets/2677334/12600172/7af28fb0-c465-11e5-85e5-3786852bf522.png">
It also changes places where we added the warnings manually to use deprecatedPropType instead.
Closes https://github.com/facebook/react-native/pull/5566
Reviewed By: svcscm
Differential Revision: D2874629
Pulled By: nicklockwood
fb-gh-sync-id: c3c63bae7bbec26cc146029abd9aa5efbe73f795