Implement multi-device

- add a spiner to wizard dialog
- use wizard dialog to migrate and add ring account
- add a device panel in account details configuration
- add "Add device" feature

Change-Id: I30955a4ef2434b1e9e9f75db39478965d6656ca0
Tuleap: #951
diff --git a/ressources.qrc b/ressources.qrc
index 69c51ca..cd0732e 100644
--- a/ressources.qrc
+++ b/ressources.qrc
@@ -39,5 +39,6 @@
         <file>images/icons/ic_photo_camera_white_24dp_2x.png</file>
         <file>images/qrcode.png</file>
         <file>images/icons/ic_share_black_48dp_2x.png</file>
+        <file>images/loading.gif</file>
     </qresource>
 </RCC>