Fix some warnings in ReactExample from RN upgrade

examples/ReactExample/components/todo-app.js

@@ -18,10 +18,13 @@
 
 'use strict';
 
-import React, {
+import React from 'react';
+
+import {
     Component,
     Navigator,
-    StatusBarIOS,
+    Platform,
+    StatusBar,
     Text,
     TouchableOpacity,
     View,
@@ -60,8 +63,8 @@ export default class TodoApp extends Component {
     }
 
     componentWillMount() {
-        if (StatusBarIOS) {
-            StatusBarIOS.setStyle('light-content');
+        if (Platform.OS == 'ios') {
+            StatusBar.setBarStyle('light-content');
         }
     }
 

examples/ReactExample/components/todo-item.js

@@ -18,7 +18,9 @@
 
 'use strict';
 
-import React, {
+import React from 'react';
+
+import {
     Text,
     TouchableWithoutFeedback,
     View,

examples/ReactExample/components/todo-list-item.js

@@ -18,7 +18,9 @@
 
 'use strict';
 
-import React, {
+import React from 'react';
+
+import {
     Platform,
     Text,
     TextInput,

examples/ReactExample/components/todo-listview.js

@@ -18,7 +18,9 @@
 
 'use strict';
 
-import React, {
+import React from 'react';
+
+import {
     Text,
     View,
 } from 'react-native';