preferences: add Settings page

* Allow user to select system contact integration
* Allow user to enable mobile connectivity

Tuleap: #102
Change-Id: Ieb161d97d5dc61b3664597def130dea6c7eefb5f
diff --git a/ring-android/app/src/main/res/menu/drawer.xml b/ring-android/app/src/main/res/menu/drawer.xml
index 0c0a18b..2c2cc83 100644
--- a/ring-android/app/src/main/res/menu/drawer.xml
+++ b/ring-android/app/src/main/res/menu/drawer.xml
@@ -11,6 +11,10 @@
             android:icon="@drawable/ic_group_black_48dp"
             android:title="@string/menu_item_accounts"/>
         <item
+            android:id="@+id/menuitem_prefs"
+            android:icon="@drawable/ic_settings_black_24dp"
+            android:title="@string/menu_item_settings"/>
+        <item
             android:id="@+id/menuitem_about"
             android:icon="@drawable/ic_info_black_48dp"
             android:title="@string/menu_item_about"/>