Added Android Expansion File Support (#142)

* Add Android Expansion File Support

* Added notes for usage with Android Expansion file

* Update README.md

Added notes re: expansion file usage.

* formatting issue fixes

README.md

@@ -116,6 +116,38 @@ var styles = StyleSheet.create({
 });
 ```
 
+
+## Android Expansion File Usage
+
+```javascript
+// Within your render function, assuming you have a file called
+// "background.mp4" in your expansion file. Just add your main and (if applicable) patch version
+<Video source={{uri: "background", mainVer: 1, patchVer: 0}} // Looks for .mp4 file (background.mp4) in the given expansion version.
+       rate={1.0}                   // 0 is paused, 1 is normal.
+       volume={1.0}                 // 0 is muted, 1 is normal.
+       muted={false}                // Mutes the audio entirely.
+       paused={false}               // Pauses playback entirely.
+       resizeMode="cover"           // Fill the whole screen at aspect ratio.
+       repeat={true}                // Repeat forever.
+       onLoadStart={this.loadStart} // Callback when video starts to load
+       onLoad={this.setDuration}    // Callback when video loads
+       onProgress={this.setTime}    // Callback every ~250ms with currentTime
+       onEnd={this.onEnd}           // Callback when playback finishes
+       onError={this.videoError}    // Callback when video cannot be loaded
+       style={styles.backgroundVideo} />
+
+// Later on in your styles..
+var styles = Stylesheet.create({
+  backgroundVideo: {
+    position: 'absolute',
+    top: 0,
+    left: 0,
+    bottom: 0,
+    right: 0,
+  },
+});
+```
+
 ### Load files with the RN Asset System
 
 The asset system [introduced in RN `0.14`](http://www.reactnative.com/react-native-v0-14-0-released/) allows loading image resources shared across iOS and Android without touching native code. As of RN `0.31` [the same is true](https://github.com/facebook/react-native/commit/91ff6868a554c4930fd5fda6ba8044dbd56c8374) of mp4 video assets for Android. As of [RN `0.33`](https://github.com/facebook/react-native/releases/tag/v0.33.0) iOS is also supported. Requires `react-native-video@0.9.0`.