refactor to be tiling window manager friendly

sources/scripts/interface.js

@@ -6,7 +6,7 @@ function Interface()
 
   this.start = function()
   {
-    document.body.appendChild(this.el);
+    document.getElementById("app").appendChild(this.el);
 
     // Interface
     var html = ""
@@ -55,4 +55,4 @@ function Interface()
     var win = require('electron').remote.getCurrentWindow();
     win.setSize(900,this.is_visible ? 420 : 400);
   }
-}
+}