Fix up this pattern var React = require('react-native');

Summary:First I searched for special cases that destructor PropTypes:

```
(?s)React\s*=\s*require\('react\-native'\).*(Children|PropTypes)[^\{\}]*\}\s*=\s*React;
```

I split them up manually.

Then I replaced the React = require('react-native') + destructuring pattern...

```
(?s)(const|var)\s+React\s*=\s*require\('react\-native'\)(.*[^\{\}]*\}\s*=\s*)React;
```

...with...

```
$1 React = require('react');
$1 ReactNative = require('react-native')$2ReactNative;
```

I used lint to figure out if I left some unnecessary imports.

Finally I grepped for just

```
React\s*=\s*require\('react\-native'\)
```

to catch any remaining patterns.

Also, `} = React.NativeModules` -> `} = ReactNative.NativeModules`.

Reviewed By: spicyj

Differential Revision: D3158991

fb-gh-sync-id: f97e8e921e193d6ea1a49d8d1bf3f09be7bed5c3
fbshipit-source-id: f97e8e921e193d6ea1a49d8d1bf3f09be7bed5c3

Examples/UIExplorer/MapViewExample.js

@@ -15,17 +15,18 @@
  */
 'use strict';
 
-var React = require('react-native');
+var React = require('react');
+var ReactNative = require('react-native');
+var { PropTypes } = React;
 var {
   Image,
   MapView,
-  PropTypes,
   StyleSheet,
   Text,
   TextInput,
   TouchableOpacity,
   View,
-} = React;
+} = ReactNative;
 
 var regionText = {
   latitude: '0',