Implement application shortcuts (fix #161)

app/src/main/AndroidManifest.xml

@@ -8,6 +8,7 @@
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
+    <uses-permission android:name="com.android.launcher.permission.INSTALL_SHORTCUT" />
 
     <application
         android:allowBackup="true"
@@ -30,6 +31,13 @@
 
         <activity android:name=".AboutActivity"/>
 
+        <activity
+            android:name=".ShortcutActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+            </intent-filter>
+        </activity>
+
         <service android:name=".TrackingService" />
 
         <service android:name=".TrackingService$HideNotificationService" />