Switch to side-by-side view

--- a/GUI/upplay.qrc
+++ b/GUI/upplay.qrc
@@ -47,6 +47,8 @@
   <file>icons/vol_3_dark.png</file>
   <file>icons/vol_mute.png</file>
   <file>icons/vol_mute_dark.png</file>
+  <file alias="volslide-inside">icons/volume-slider-inside.png</file>
+  <file alias="volslide-outside">icons/volume-slider-outside.png</file>
 </qresource>
 </RCC>