add auto start option

AndroidManifest.xml

@@ -2,12 +2,13 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="com.github.shadowsocks"
           android:installLocation="auto"
-          android:versionCode="3"
-          android:versionName="1.0.2">
+          android:versionCode="4"
+          android:versionName="1.1">
 
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
     <uses-permission android:name="android.permission.WAKE_LOCK"/>
+    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
 
     <uses-feature
             android:name="android.hardware.touchscreen"
@@ -41,6 +42,12 @@
                 android:name=".ShadowsocksService"
                 android:enabled="true"/>
 
+        <receiver android:name=".ShadowsocksReceiver">
+            <intent-filter>
+                <action android:name="android.intent.action.BOOT_COMPLETED"/>
+            </intent-filter>
+        </receiver>
+
     </application>
 
 </manifest>