Update Image docs and examples to the new asset system

Summary:
After the release of 0.14, static images should be placed in the source code tree and then required as explained in the [Images guide] (https://facebook.github.io/react-native/docs/images.html). This pull request updates the image documentation and examples to the new asset system. UIExplorer tested on iOS and Android.
Closes https://github.com/facebook/react-native/pull/4987

Reviewed By: svcscm

Differential Revision: D2796276

Pulled By: bestander

fb-gh-sync-id: 732ffa2f136391bb8a3e40a54b5b1ff5022c97f2

Examples/UIExplorer/ImageExample.js

@@ -148,15 +148,15 @@ exports.examples = [
   },
   {
     title: 'Plain Static Image',
-    description: 'Static assets should be required by prefixing with `image!` ' +
-      'and are located in the app bundle.',
+    description: 'Static assets should be placed in the source code tree, and ' +
+    'required in the same way as JavaScript modules.',
     render: function() {
       return (
         <View style={styles.horizontal}>
-          <Image source={require('image!uie_thumb_normal')} style={styles.icon} />
-          <Image source={require('image!uie_thumb_selected')} style={styles.icon} />
-          <Image source={require('image!uie_comment_normal')} style={styles.icon} />
-          <Image source={require('image!uie_comment_highlighted')} style={styles.icon} />
+          <Image source={require('./uie_thumb_normal.png')} style={styles.icon} />
+          <Image source={require('./uie_thumb_selected.png')} style={styles.icon} />
+          <Image source={require('./uie_comment_normal.png')} style={styles.icon} />
+          <Image source={require('./uie_comment_highlighted.png')} style={styles.icon} />
         </View>
       );
     },
@@ -320,19 +320,19 @@ exports.examples = [
         <View>
           <View style={styles.horizontal}>
             <Image
-              source={require('image!uie_thumb_normal')}
+              source={require('./uie_thumb_normal.png')}
               style={[styles.icon, {borderRadius: 5, tintColor: '#5ac8fa' }]}
             />
             <Image
-              source={require('image!uie_thumb_normal')}
+              source={require('./uie_thumb_normal.png')}
               style={[styles.icon, styles.leftMargin, {borderRadius: 5, tintColor: '#4cd964' }]}
             />
             <Image
-              source={require('image!uie_thumb_normal')}
+              source={require('./uie_thumb_normal.png')}
               style={[styles.icon, styles.leftMargin, {borderRadius: 5, tintColor: '#ff2d55' }]}
             />
             <Image
-              source={require('image!uie_thumb_normal')}
+              source={require('./uie_thumb_normal.png')}
               style={[styles.icon, styles.leftMargin, {borderRadius: 5, tintColor: '#8e8e93' }]}
             />
           </View>

Examples/UIExplorer/MapViewExample.js

@@ -313,7 +313,7 @@ exports.examples = [
             }}>
             <Image
               style={{width:30, height:30}}
-              source={require('image!uie_thumb_selected')}
+              source={require('./uie_thumb_selected.png')}
             />
           </TouchableOpacity>
         ),

Examples/UIExplorer/UIExplorer/Images.xcassets/uie_comment_highlighted.imageset/Contents.json

@@ -1,21 +0,0 @@
-{
-  "images" : [
-    {
-      "idiom" : "universal",
-      "scale" : "1x"
-    },
-    {
-      "idiom" : "universal",
-      "scale" : "2x",
-      "filename" : "uie_comment_highlighted@2x.png"
-    },
-    {
-      "idiom" : "universal",
-      "scale" : "3x"
-    }
-  ],
-  "info" : {
-    "version" : 1,
-    "author" : "xcode"
-  }
-}

Examples/UIExplorer/UIExplorer/Images.xcassets/uie_comment_normal.imageset/Contents.json

@@ -1,21 +0,0 @@
-{
-  "images" : [
-    {
-      "idiom" : "universal",
-      "scale" : "1x"
-    },
-    {
-      "idiom" : "universal",
-      "scale" : "2x",
-      "filename" : "uie_comment_normal@2x.png"
-    },
-    {
-      "idiom" : "universal",
-      "scale" : "3x"
-    }
-  ],
-  "info" : {
-    "version" : 1,
-    "author" : "xcode"
-  }
-}

Examples/UIExplorer/UIExplorer/Images.xcassets/uie_thumb_normal.imageset/Contents.json

@@ -1,21 +0,0 @@
-{
-  "images" : [
-    {
-      "idiom" : "universal",
-      "scale" : "1x"
-    },
-    {
-      "idiom" : "universal",
-      "scale" : "2x",
-      "filename" : "uie_thumb_normal@2x.png"
-    },
-    {
-      "idiom" : "universal",
-      "scale" : "3x"
-    }
-  ],
-  "info" : {
-    "version" : 1,
-    "author" : "xcode"
-  }
-}

Examples/UIExplorer/UIExplorer/Images.xcassets/uie_thumb_selected.imageset/Contents.json

@@ -1,21 +0,0 @@
-{
-  "images" : [
-    {
-      "idiom" : "universal",
-      "scale" : "1x"
-    },
-    {
-      "idiom" : "universal",
-      "scale" : "2x",
-      "filename" : "uie_thumb_selected@2x.png"
-    },
-    {
-      "idiom" : "universal",
-      "scale" : "3x"
-    }
-  ],
-  "info" : {
-    "version" : 1,
-    "author" : "xcode"
-  }
-}

Libraries/Image/Image.android.js

@@ -38,7 +38,7 @@ var resolveAssetSource = require('resolveAssetSource');
  *       <View>
  *         <Image
  *           style={styles.icon}
- *           source={require('image!myIcon')}
+ *           source={require('./myIcon.png')}
  *         />
  *         <Image
  *           style={styles.logo}
@@ -66,8 +66,8 @@ var Image = React.createClass({
     style: StyleSheetPropType(ImageStylePropTypes), 
    /**
      * `uri` is a string representing the resource identifier for the image, which
-     * could be an http address, a local file path, or the name of a static image
-     * resource (which should be wrapped in the `require('image!name')` function).
+     * could be an http address, a local file path, or a static image
+     * resource (which should be wrapped in the `require('./path/to/image.png')` function).
      */
     source: PropTypes.oneOfType([
       PropTypes.shape({